Well, I would write a long post but that's been done already by everyone else.
I mean, I don't even need to plug my games anymore, everyone else does it for me
So yeah, welcome, what they said, yada yada
EDIT: oh, and to clarify what Celtia said about game systems: for one, most of the systems used here are homebrew or published-but-so-modified-they-may-as-well-be-homebrew, so nobody expects you to really know the system in play.
In any case, most GMs are happy to deal with the number crunching and let you play