Star Fleet Battles LinksOfficial Site
Star Fleet Headquarters - The offical ADB site.
Star Fleet BBS - The official Star Fleet Universe discussion boards.
Federation Commander - The official website for Federation Commander.
Federation Commander Forums - The official Federation Commander forums.
(Apparently all of these sites are now gone. What a shame.)
John Kim's Unofficial SFB Site - Now long defunct, it had tons of fun, useful ideas and SSDs.
PHD Shipyards - Hundreds of new ships, most of which are reasonable designs, as opposed to the monstrous designs you usually find. (Though they do have some of those, too!) Also has some ideas for the Early Years Federation National fleets.
Art Braun's (aka NeghVar) Web Page - This is the only other site, besides this and John Kim's pages, that has extensive Early Years coverage. Has some other stuff too, especially lots of fighter additions.
Andy Palmers' Sub-Light Web Page- Sublight rules and ships.
James Jarvis' Sublight and Slow Warp Site- Sublight and slow warp rules and ships.
Ted Geibel's Star Trek 3D Gallery - Has 3D pictures of several SFB ships, like the Fed CA, DD and Orion CA. He has done a great job with the pictures and even takes suggestions. (The NCL was mine!)