Check out my airport holding company (I am the CEO) - The cities are the train layouts the airports go with
Sault Ste. Marie (Ontario) Airport - the prototype for my main airport model
Milwaukee's General Mitchell Intl. - Wisconsin's largest and busiest
Madison, WI/Dane County Regional - Wisconsin's second-largest airport
Green Bay Austin Straubel Intl. - our third largest
Frankfurt Main - Europe's version of O'Hare
O'Hare, Midway, Meigs & the other Chicago-area airports
Munich's Frans Josef Strauss
Unique - Zurich's airport
Toronto - Canada's largest and busiest
Vancouver - Canada's second-busiest
Airline Photos - the most comprehensive I've seen.
Airport info - runway lengths, FBOs, fuel types, etc. for American airports.
FAA info - want to build your own airport in your backyard? Here's what you need to know!
Orbitz
Airlines can be found on the airport websites
Herpa - the most popular. In 1:200, 400 & 500 scales.
Sky's the Limit
Airline Museum
Airplane Superstore
Just Plane Fun
Wings 900 - Comprehensive model airplane-related site.
Any more? Email me!