Someone probably already mentioned this:
http://www.flightglobal.com/sitemap/default.aspxThis archive of Flight magazine (1909-2004) has lots of interesting and informative articles, photos and drawings.
For example there are fairly in-depth looks at German aircraft going through details of structural design etc. including 3D cutaways.
It's fascinating reading articles written as perceived at the time.
Quite often opinions of aircraft are influenced by propaganda, example: in January 1942 they make first mention of the FW190, saying it doesn't really measure up to the Hurricane or Spitfire.
An otherwise excellent article on the Short Stirling lists maximum speed as "around" 300mph (I guess around means +/- 50mph)