I'd say HTML with a few well integrated Flash bits (perhaps a navigation in Flash) would go a long way in the FIRST Web world. The web is evolving into a more multimedia rich environment so Flash is your friend. Don't try to get fancy with programming, leave that stuff for the robot
Just make your pages in HTML using tables (no frames/i frames) with perhaps a exterior/embeded CSS page to work your links and text font, color, decoration. A little interactivity goes a long way. Use interactivity in your buttons, simple rollovers are fun to play with
Remember, although trying to win the web award should be a goal think more in the lines of "will this website be useful to anyone wanting to find more info about Team 45, FIRST and the rest of the community?" Think of ways to make your website different from all the rest out there. You'd want to stand out in aesthetics, functionality AND performance. Triple threat