Long Island is an island stretching eastward from New York City in the Metro New York region. The largely suburban area is approximately 115 miles long from Brooklyn and Queens at the western end, to Montauk at the easternmost point. At its widest the island is approximately 20 miles from north to south. While Long Island geographically includes Brooklyn and Queens, politically Long Island in general only includes Nassau County and Suffolk County of New York State only.
While Long Island is home to seven million year-round locals, many commuting in and out of New York City, the Island is home to a lot of discreet tourism (concentrated in certain towns—Huntington, Fire Island, Montauk) and also serves as the zip code for the vacation homes of many wealthy city dwellers, particularly in the Hamptons.
Geographically, Queen and Brooklyn are part of Long Island but are usually associated more as 2 of the 5 New York City boroughs. When Long Islanders talk about Long Island they are typically referring to only Nassau and Suffolk County.
Long Island is essentially a suburban area throughout (except for the Twin Forks region, which is rural) and has few major towns.
From a tourist's point of view, Long Island is most ideal to visit in the summer due to all the beaches, but no matter the season there is always something to do. Long Island is great place to visit whether it be for a family vacation, a group of 20-somethings looking to rent a summer house, or an older retired couple looking to enjoy some natural sight-seeing or tour a museum.
Nassau County and Western Suffolk County is very developed and densely populated, and is home more to the 'suburbia' type neighborhoods Long Island became famous for after World War II, where most year-round residents live. (i.e. Levittown, Oceanside). Central and Eastern Suffolk County, however, is somewhat rural (for the New York area, anyway) and is home to much agriculture, wineries, and beach towns. Many summer homes and hotels are located here, and is where most wealthy New Yorkers congregate in the summer months when the concrete jungle is too hot to bear. Tourist attractions can be found equally in both counties and throughout the entire Island.
Long Island's only downside to tourism is harsh north-eastern winters that make traveling somewhat difficult, and the fact that it is an expensive place to both live as a permanent resident and also as a tourist. There are towns that are more friendly to the wallet than the notoriously expensive Hamptons, or "Gold Coast" North Shore towns, however, Long Island is home to some of the most expensive zip codes in the entire world. Do not expect a bargain vacation when traveling to Long Island, or anywhere in the New York Metropolitan area for that matter.
For those that wish to make Long Island their home, it should be pointed out that Long Island is the most expensive place in the United States to live due to the high cost of living, 8th highest electric rates, high taxes on fuel and gasoline, very high property taxes and astronomical home prices.
The Long Island Conventions & Visitors Bureau  provides information about Long Island and the places to visit.
The Long Island Railroad  runs from Pennsylvania Station in Manhattan to various points on Long Island on many branches. Service is not as frequent as the NYC subways. Remember to buy tickets at stations, as buying on-board cost extra. (Note that fares increased for all MTA services on March 22, 2015)
There are several ferry services that can be found on Long Island.
Ferry Services to Connecticut, Rhode Island and Block Island
Ferry Services to Shelter Island
Ferry Services to Fire Island
When traveling along the North Shore, you may take the scenic and relaxing route of 25-A, a single lane road that runs through historic, wealthy towns on the northern shore.
Please understand that Long Island is a very large island. At 118 miles in length, it can take hours to travel from one destination to another, especially during morning and afternoon rush hour when the main roads suffer from high congestion and the trains are crowded.
There are two main bus operators on Long Island: Nassau Inter-County Express (the former Long Island Bus) in Nassau and Suffolk County Transit in Suffolk. Each maintain extensive bus networks throughout their counties. Connections to the MTA Queens Buses are availible from NICE, as well as connections between Nassau and suffolk. (Almost all NICE routes into Queens drop off passengers going west and pick up going east only.) For schedules, fares and route maps for NICE, visit their website: . For the same for Suffolk Transit, visit their website: 
The Long Island Rail Road crosses the entire island, with stops in virtually every community of note. Please not that it is designed to take residents into and out of Manhattan, so connections between branches are virtually nonexistent. However, with the exception of the Port Washington line, every branch does come into Jamaica station in Queens, so if you do need to change branches, Jamaica is where you will likely do it.
The Port Jefferson branch goes all the way out to Port Jefferson on the north shore in Suffolk County. The Ronkonkoma branch goes to Greenport on the north fork. The Montauk branch goes to its namesake hamlet on the tip of the south fork. The Hempstead and West Hempstead branches go into the heart of Nassau County. The Far Rockaway and Long Beach branches carry beach goers from the city to the popular beaches on the south shore.
For schedules and fares, visit the LIRR website: 
In addition to highways getting into Long Island, there are more to get around:
The Long Island Expressway (the L.I.E.) has the high-occupancy-vehicle (HOV) lanes in both directions in Nassau and western Suffolk Counties. From 6 am to 10 am and 3 pm to 8 pm from Monday to Friday, it can save time for motorcycles (even without passengers) and cars with at least two occupants.
It is extremely recommended that you use an HOV lane if possible! Traffic jams can last for hours and disrupt travel plans. Just make sure that you know what exit you will get off at. There are only certain points at which you can get out of the HOV  lane.
The Meadowbrook Parkway runs from Jones Beach, through Long Beach connecting the South Shore towns to Mineola and The Northern Parkway.
The vast majority of Long Islanders speak English as their first and primary language, however there are significant communities of Spanish, Italian, Russian, and Polish speakers in various areas. While visiting Long Island, natives will expect to be spoken to in English, and while Spanish, Italian, and French are taught in the majority of Long Island schools, most Long Islanders will have limited, but some knowledge, and may be able to converse with you in your language. The Long Island dialect of English is very similar to the English spoken in Northern New Jersey and New York City, yet still with some differences. The average tourist will not be able to tell a Long Islander from someone from Brooklyn or Queens, but to natives the dialects are clearly distinct.
Some features of a Long Island dialect would be the absence of the Mary-marry-merry merger, the absence of the cot-caught merger, nasal tones, and the emphasis on consonants such as "g" (as evident in "Long Island" being pronounced "Lawn Guyland" by a native Long Islander with a heavy accent). Despite these differences, a Long Island dialect will still be fairly easy to understand for other Americans and Canadians, and although harder for Brits or Australians, still generally understandable.
The primary tourist attractions are the large number of excellent beaches along Long Island Sound on the North Shore (the setting of the famous novel and movie "The Great Gatsby", and the more famous South Shore, which is home to the Atlantic Ocean's waves and white-sand beaches.
The North Fork is also home to many wineries, farms and culinary outlets.
Other attractions include North Shore harbor towns such as Port Jefferson, Huntington Village, Stony Brook and Northport where a variety of eateries and small businesses thrive in a bohemian atmosphere.
LearnLong Island is also the home to Stony Brook University, one of the top-100 Universities (US News and World Report), which is part of the State University of New York (SUNY) system, providing a very academic and international community within central Long Island. Brookhaven National Laboratory, affiliated with the U.S. Department of Energy, and Cold Spring Harbor Laboratory is also located on Long Island. Both labs are affiliated with Stony Brook University.
Another well known university is Hofstra University located in Hempstead is the largest private university on Long Island. Long Island is also the home of Nassau County Community College, the largest community college in New York. Other noteworthy institutions of higher learning are Adelphi University, Malloy College, CW Post, NY Institute of Technology, Suffolk County Community College, Queens College, United States Merchant Marine Academy and the Webb Institute.
Long Island is a lot like New Jersey and parts of Connecticut in as much as a there are a lot of 24 hour diners that serve pretty much anything whenever. Young people congregate in these diners at odd hours, and they can be found spread out on the major roads like Jericho Turnpike or Sunrise Highway. There are also many seafood restaurants (especially with local clams and mussels-local Long Island specialty foods). Because there are so many local restaurants, (many Zagat rated), with influence from European families and the nearby international cuisine of New York City, a Long Islander wouldn't recommend to eat at a chain restaurant that could be found anywhere such as Applebee's, the Olive Garden or Red Lobster. They are of course readily available on Long Island, but it is really a shame to not try privately owned eateries that are equally priced but more distinct than the chain restaurants. Try one of the following:
Many major fast food chains and chain casual dining restaurants have locations on Long Island. Deer Park Avenue is said to have the most fast food places on one road.
Be sure to visit a local farmstand, especially those out east and on the North Fork. Local produce and farming is a major industry on Long Island.
The well known cocktail, the Long Island Iced Tea, was first created on Long Island. One of the most celebrated local beers is called Blue Point , named for the town of the same name.
Drinking on Long Island is tough because you need a car to get around, with this in mind, use the Long Island Railroad to your advantage. Take it from town to town, or take a night out to go into the City. At night, there is little public transportation besides LIRR, but there are taxis. The South Shore in Nassau County has some good bars, (with a somewhat rowdy crowd, however).
On the North Shore you will find a buzzing college-bar scene year-round, mostly for those college students and other 20-somethings looking for a night out that doesn't involve a dorm party, frat or sorority or an expensive trip to NYC. The most popular towns for this kind of bar-scene are Huntington Village, Port Jefferson, (both along Route 25-A) and recently Smithtown along Jericho Turnpike/Route 25, which has developed as an up and coming bar scene by night despite their charming shopping and family-oritented atmospheres by day.
Be smart, don't travel to towns with a lot of crime at night. These towns include: Roosevelt, Hempstead, North Amityville, North Baldwin, Wyandanch, Rosedale, North Bay Shore, Central Islip, New Cassel, eastern Westbury, northern West Babylon, Uniondale and Freeport. Most notably is Brentwood and Farmingville where the gang MS-13 has been terrorizing the area for 20 years. Other notable gangs such as the Bloods, Crips, Latin Kings, Sureños and the 18th Street Gang also are present in these communities. In the daytime, these areas aren’t always secure and shootings can and do still happen in broad daylight.
Other than those towns, which most locals could tell you is where most of the dangerous crime occurs, crime on the rest of Long Island is related to drug-arrests and burglarlies of high-end neighborhoods.
Most robberies are related to hired help, and are low-profile crimes. However, the most recent epidemic crime problem has been the epidemic increase in heroin use among Long Island teens, particularly of wealthier neighborhoods along the North Shore. Generally, this should not be a problem for a tourist.
Nassau and Suffolk Counties each have a police department, as well as many local departments located throughout the island.
Homosexuality is not received well here. Long Island is a very conservative area where homosexuality is seen as a sin. Catholicism and other Christianity is very devoutly followed here so homosexuals will not be welcomed and may face discrimination and higher risk of assaults. Police may turn a blind eye and have negative views as well so don't rely on them. Avoid visiting if you are LGBT.
Increasing numbers of reports of racist "go back to your country" attitudes have arisen in Long Island. Extra caution should be had at night or in neighborhoods that tend to be less diverse. Sadly, Long Island tends to be segregated with most of the areas with more diversity being in areas away from the the main attractions in town.
Long Islanders in general, do not differ greatly from others in the Northeastern region of the United States, especially those from the rest of New York and nearby New Jersey in terms of acceptable social behavior. Talking to strangers is widely uncommon and small talk is generally disdained by Long Islanders. However, the harmless act of asking for directions will likely go over okay with a Long Islander, but do not be surprised if they simply ignore you and go on with their day upon trying to talk to them. While in public, it is very important to keep your distance from strangers, as someone getting too close is often worrisome and may cause problems.
While riding public transport, it is considered highly unacceptable and rude to sit directly next to someone while there are other seats available, such as on a train or bus. Despite being acceptable in other parts of the United States, striking up conversations with cashiers or just in general strangers will likely not go over well. Although the person will likely be civil towards you, do not expect them to be overly engaged in the conversation and they will likely try to end it quickly. Long Islanders are very kept to themselves in comparison to people from other parts of the country, so it should be known that unless they initiate the conversation, they will most likely feel very uncomfortable. Taking pictures of strangers without their permission or knowledge will likely go over very poorly and could lead to altercation.
One of the biggest safety hazards Long Islanders face when preparing for natural disasters such as hurricanes is the lack of ways to get off the Island. There really is only one immediate way out via car- through the highly congested bridges of New York City. You may also exit via Ferry to New England, or fly out of one of the three major airports. (One on LI, 2 in NYC)
You may leave Long Island to go on day trips to any borough of New York City, Connecticut, New Jersey, upstate New York (another great place to visit)...however, there are so many day trips that can be spent on the Island itself with it's many unique towns and other nooks and crannies, that it is advised by locals to plan on staying on Long Island if you plan a trip here and seep into local life as much as possible. It is very common for Long Islanders to never leave the Island during summer vacations because there is so much to do in the summer even for locals. The Island itself is large, and one can live on Long Island their entire life and still find something new to do or explore on the very same island each summer. On Long Island, there is no manufactured fun. It is all about exploring the communities and natural scenery for what they are to year-round residents. Long Island is not built for tourists like Florida's Disneyworld might be, however, ironically, that makes for the best kind of tourism.
One of the biggest hot spots for tourists and vacationers alike to go to is Montauk located at the farthest eastern end of Long Island. In the summer it is a mecca for young people to drink and party during which time hotel rates quadruple in price. Getting into Montauk during the summer can take several hours by car as traffic can be backed up for miles. During the fall, winter and early spring the town is almost a ghost town and room rates are a lot more affordable. Montauk has been listed as the most expensive place to stay in New York State.