Hmm, well the majority of boards I know of are largely involved with a single game line, such as Dungeons and Dragons, World of Darkness, etc.
Now, the core rules for D&D are available for free online(legally, in case you're wondering, due to the Open Game Content, everything you need to play can be found here
http://www.d20srd.org/ )
Here's a list of sites for D&D
http://dicefreaks.forumz.cc/index.php The other board I'm a regular member of, there's usually a game or three going on, though I imagine they're all a bit out of your league at the moment, even if you did actually put in the time needed to wrap your head around D&D)
http://wizards.com/ The publishers/creators of modern D&D, I don't actually browse their site often, but the forums likely have a handful of games running, or people willing to start one.
And then there's
http://www.enworld.org/forum/ which is probably guaranteed to have someone willing to join you in whichever roleplaying adventures you like.
Last amongst those I have bookmarked is
http://forums.white-wolf.com/cs/ They're the creators/publishers of World of Darkness(Vampire, Werewolf, Mage, Changeling, Promethean, etc) and Exalted, and Scion. If you can think of it chances are that they've written something for it. You might be able to find some roleplaying fun there.
I'm not all that big on the FFRPG scene, which is to say not at all, so I wouldn't really be able to recommend anything along those lines.
As long as it is a good forum, I do not care if it is a Free-Form or a rule sets forum.
