More sites for the collection:

Aerodynamics animated using flash animations.
http://142.26.194.131/aerodynamics1
(I hope that's a static IP address - I can't locate a domain name for it.)
This comes from Selkirk College in British Columbia, Canada.

Ground School, by the Australian Ultralight Federation
As an online resource, I thought it worthwhile.
http://www.auf.asn.au/groundschool/contents.html

"See How It Flies - A new spin on the perceptions, procedures, and principles of flight. "
One persons self published, on line, book about flying.
http://www.av8n.com/how