Here are some good links for skins, meshes, help and discussions about Freedom Force.
The Skindex - http://www.darkjared.addr.com/ff/ffmain.htm
Another site with a lot (and I mean a LOT) of great skins by some fantastic artists, but I think the best thing about it are the two tutorials that DarkJared put together on Skinning and using the Alpha Channel. I was able to learn how to skin because of those tutorials...and it is NOT easy to teach this old dog a new trick. Thanks, DarkJared, for your hard work!
Freedom Force Center - www.freedomforcecenter.com
Let's face it, if you haven't been to this site already, you probably haven't been playing the game long. This is the only site with more skins on it than The Skindex, but the quality of them varies considerably more. There are some definite gems there, though (like the Colonel Sanders skin...and I thought I skinned weird things) and is a great repository for news on the game and new meshes, etc. The Effects models for the game were first posted there, if I recall, so it is definitely worth your time to take a gander there once in a while.
Ooleyman's Freedom Force Page - http://ooleyman.home.attbi.com/index.htm
Ooleyman has done a great job modifying a lot of meshes, especially the female ones. This is the site to find:
Alex's Freedom Fortress - http://www.raventg.com/ff.nsf/All/Home
Alex has a number of recipes/hero files for popular characters, but I think his greatest contribution is his E-Z Danger Room mod. Great way to get the hang of multiplayer action before jumping into a game.
This was the first skin site I went to and I think it is still one of the best, and one of the few that has a lot of Golden Age characters on it. Psycho-Pirate has skinned most of the Justice Society of America, the All-Star Squadron, The Phantom and his friends, the Thunder Agents and a bunch of cool villains, including his namesake.
Heroes for Hire - www.heroesforhire.net
This site has some of the true mesh-masters of the game (Gyruss, The Beyonder, JiK) and has some of the best custom meshes you'll find out there right now. This is the place to go for:
X-Man's Freedom Force Skins - http://cs-people.bu.edu/colstad/freedomforce/
Another site with some essential (or soon to be essential) meshes for the skinner who wants a little more. Here you'll find (besides a bunch of cool skins):
Th Gryphon's Skins - http://www.chynaman.pwp.blueyonder.co.uk/FF/FF.html
This guy does some FANTASTIC work! And I personally believe that nearly every skinner out there now owes him a big debt of gratitude for the fantastic base skins that he did. Folks, make sure you give credit where credit is due...if you used one of Gryphon's base skins, mention it in your info file (and that goes for anyone else's skins you base your own work on too).
Zed's Skin Center - http://members.cox.net/horton551/index.htm
A lot of very nice skins...and another guy who did some very good base skins for the custom meshes.
GummOmega - http://www.gummo-vision.com/gummomega/
Great skins, with some primo Marvel characters (Venom, Thing and the Absorbing Man are my personal favorites).
Tortuga's Freedom Force Site - http://members.shaw.ca/ajhopkins/skins.html
Some great original skins.