Fukuoka has a very old history and has had close contact with Japan's Asian neighbors, including the site of two Mongolian invasions in the late 13th century that were unsuccessful (due to typhoons, hence the term kamikaze). Its port has been used extensively in Japan's early history and is the entry point for the spread of Buddhism.
It's possible for English speakers to navigate their way around without speaking any Japanese. Signs at subway and train stations include the station names in romaji (Romanized characters). Though most people under the age of 40 studied English in school, proficiency is generally poor, and most locals would not know more than a few basic words and phrases. Some restaurants may have English menus, but it does not necessarily mean that the staff will speak much English. Reading and writing comes much better though, and many people can understand a great deal of written English without actually knowing how to speak it. That being said, staff at the main hotels and tourist attractions generally speak an acceptable level of English. While it is possible to get by with only English, it will nevertheless make your trip much smoother if you can learn some basic Japanese.
Fukuoka city's airport is the busiest on Kyushu and fields a fair number of international flights too, e.g. to South Korea, China and Taiwan. Finnair has regular direct flights between Helsinki and Fukuoka three times a week. It also has connections in Japan to fifteen other major Japanese cities. The airport is considered one of the most convenient airports in Japan and the only airport in Japan that is connected to a subway line.
Kitakyushu also has an airport but it is mostly served by commuter flights to and from Tokyo's Haneda Airport with some service to Naha. There are also regularly scheduled international flights to Seoul and Busan, South Korea. The airport is situated on an artificially constructed island in the Seto Inland Sea and is one of the few airports in Japan that operates 24 hours a day. There is no direct rail access to the Kitakyushu Airport but there are ferry buses to nearby train stations and bus terminals.
Fukuoka City and Kitakyushu City are both on the shinkansen line that runs to and from Tokyo. The JR train system has several lines running across the prefecture, as well as from the Meinohama subway station in Fukuoka City to Karatsu in Saga. The Kyushu shinkansen lines starts in Fukuoka City at Hakata Station and allows quick connections to Kurume, Kumamoto, and Kagoshima.
Trains and buses travel to nearly all cities and towns, with the exception of a few isolated mountain areas. Taxis are abundant also but can be expensive, even by Japanese standards. Fukuoka City also its own subway, and Kitakyushu has its own rail and monorail system. As in many other Japanese cities, JR runs the largest system, but another private rail company, Nishitetsu, also runs a heavily used rail line between Tenjin Station in Fukuoka City to Omuta, with local, express, and limited express trains. There is no difference in fare based on the faster trains, and the limited express trains travel between Fukuoka City and Omuta in about 1 hour.
Fukuoka offers a lot of the city life in Fukuoka City and Kitakyushu but still offers a lot of nature hiking, natural gardens, traditional crafts, and some of the oldest temples, shrines, and festivals in Japan. Even better is that the best places are not overrun by tourists and it is still possible to enjoy a leisurely adventure.
During the winter months (through February), take a ride down a scenic canal in Yanagawa in one of 150 small "kotatsu-bune" boats. In the boat, you keep your legs covered with a "kotatsu" quilt, while sitting at a low table equipped with a charcoal braziers. During the ride you can often enjoy cups of hot sake and mikan (mandarin orange) citrus fruits, common to this area during the winter months.
The local speciality is a version of ramen made from boiled pork bones, known as tonkotsu ramen. It is widely available from a number of street stalls called yatai on the streets of Fukuoka City and Kurume, as well as at the Ramen Stadium in the Canal City entertainment complex. Also famous is the spicy salmon cod roe called mentaiko, those nowadays all is actually imported.
Fukuoka City hosts the largest entertainment district in Western Japan (i.e., west of Osaka). Situated on the islet of Nakasu between two rivers, with downtown Tenjin on the one side and the transport hub Hakata on the other, there are literally thousands of restaurants, clubs, hostess bars and other adult venues to whet the appetite of the fearless traveller. Be warned though, you are best going with a Japanese native, if only to be able to discover the reasonably priced outlets amongst a sea of bunny girls and drunk salarymen.