Free online classified ads and job posting at Astanda.com
http://www.modelaircraft.org/
AMA is a self-supporting, non-profit organization whose purpose is to promote development of model aviation as a recognized sport and worthwhile recreation activity.
http://www.aeroplanner.com/
Offers online flight planning, sectional charts, and weather outlooks.
http://www.airliners.net/
Photo gallery containing mostly commercial airliners but also military planes and helicopters. Also hosts a discussion forum and an aircraft data and history section.
http://www.airways.co.nz/
Providing air traffic control services for New Zealand and the Auckland Oceanic Flight Information Region.
http://dir.salon.com/topics/p_smith/
Patrick Smiths weekly column on aviation on salon.com.
http://aviation.about.com/
Aviation links, all categorized, annotated and regularly reviewed, plus articles and chat.
http://williams.best.vwh.net/avform.htm
Introduction to the mathematical processes used in navigation including great circle navigation theory.
http://www.aviationtoday.com/
Aviation business intelligence.
http://www.avweb.com/
Aviation magazine and news service featuring aviation news, articles, searchable aviation databases, and on-line shopping.
http://www.brakesoff.com
Airport database with user comments.
http://www.bhpa.co.uk/
Details on how to learn to fly, lists of clubs, events, and a members area.
http://www.snowbirds.dnd.ca/
Canadian 9-plane formation team. Includes pilot bios, schedule, multimedia, sponsor guide, and guestbook.