North Seattle is a loosely-defined area, often including anywhere north of the Ship Canal that bisects the city. This article covers only the area between 85th St. and the city limits at 145th St. The neighborhoods to the south are collected in Ballard and the University District; to the north is the suburban city of Shoreline.
From west to east, the neighborhoods in North Seattle include Broadview, Bitter Lake, North Park, Haller Lake, Northgate, Maple Leaf, Pinehurst, and Lake City. The area is almost entirely residential, with the exceptions of the sprawling Northgate Mall, the gritty (albeit slowly gentrifying) commercial strip along Lake City Way, and the grittier (and staying that way) Aurora Avenue. There are few attractions of general interest,
Lake City's main drag, Lake City Way, while still the host of some creepy dive bars, thrift/pawn stores, and used car dealerships, is the focus of most urban development. New restaurants offering international cuisine are opening, and a 24 hour Starbucks is a sign that yuppie culture has arrived in Lake City.
Major streets running north-south include Greenwood Ave, Aurora Ave, I-5, and Lake City Way (SR-522). For best results, go as far as you can on one of those streets before turning off. East-west streets are often interrupted by terrain and other obstructions - try using 130th St and 105th St west of the interstate, 125th St and Northgate Way (effectively 110th St) east of it. At the city line, 145th St is unbroken all the way across.
The Northgate Transit Center, immediately south of the mall, is the hub for local service, as well as the Route 41 express bus to downtown and the 66/67 to the University District. The park-and-ride lots on all sides are free. Although the 41 runs frequently, neighborhood routes often drop down to hourly or half-hourly service. Using Metro Transit's trip planner  in advance is recommended.
Most runs on the 41 continue to Lake City Way, also served by the 72 (local service to the U-District) and 522 (express to downtown, no stops south of 125th St).
There are also, in the grand Seattle tradition, two Thai places right across the street from each other on Lake City Way: Chang's Thai and Thai One On (the latter being the better), as well as Toyoda Sushi and, a little west of downtown Lake City, the Enat Ethiopian restaurant.
Further south on Lake City Way, new development is taking place where Lake City meets the considerably nicer Maple Leaf.
For authentic Mexican food a world removed from the cliched, Americanized fodder served by chains, there is Mr. Villa near the intersection with 15th Ave. The tacos al carbon, homemade tortillas, and green salsa are not to be missed.
On 15th less than a block away is Anita's Indian Bistro which was voted 2nd best Indian food in Seattle, with rich and flavorful curries also available as sides for dipping naan.
Dick's Drive-In - Best food in Lake City (4 other around Seattle)
The Sugar Shack, a newly opened bakery near the intersection of Lake City Way and 15th, supplies an ever changing selection of cholesterol-boosting treats sure to please the palate and necessitate some cardiovascular exercise.
The Pho Binh on Lake City way offers fantastic Pho and Vietnamese sandwiches.
True to Seattle form, Starbucks are everywhere as are drive through coffee huts. If you are looking for alcoholic refreshments, there are numerous neighborhood pubs, just ask around. In general, the further north you get, the fewer options you have.
There are nearly no lodgings worth considering in North Seattle. Stay with friends, or look for more plentiful options downtown or in the U-District. On the other hand, the few options are often inexpensive compared to downtown. Avoid Aurora Avenue's hotels, which are mostly hourly rate and highly sketchy.
All branches of the Seattle Public Library offer free wireless access. Use of public, Internet-connected computers for up to an hour at a time is also free, though if you don't have a SPL library card, you must request a temporary login from the circulation desk.
Wi-fi is de rigeur in any self-respecting coffee shop.