Cycle Expo Much useful here including an HPV Links page and addresses and phone numbers for many cycling industry companies.
VeloNet Huge resource for cycling info 2500 bike related web sites and much more.
Harris Cyclery - articles by Sheldon Brown and others. IMHO The Best Bicycle Site on the Net. Nothing recumbent specific, but vast amounts of useful info. The most impressive part of this site is Sheldon's illustrated Bicycle Glossary.
Mike Iglesias's Bicycle FAQ, with lots of answers to lots of frequently asked questions:
Adventure Cycling/BikeCentennial magazine
Jane Thomas's site has a lot of useful info on S-A hubs. Don't be put off by the reference on the intro page to a 1956 manual - there is some much more recent information as well.
gearhead.com An OnLine Bike Magazine. They also sell stuff, but it's no more commercial than paper bike mags. Check out their "Reader Submitted Tips and Techniques" at Patchkit
Joshua Putnam's Bicycle Pages Nice site with Tech. articles, Ride Reports and Links. Lots of good Framebuilding info