On the PDAS Site, there are pages
that focus on
Aeronautical Information, and
Links to Aeronautical Sites.
On this site, there are pages that focus on NASA and Launch Vehicles.
The first place you would want to look is the interactive textbook by Ilan Kroo. You need a Java-enabled browser.
Also, the Aircraft Design interactive textbook.
There are several interesting pages at the Virginia Polytechnic Site