That's basically it. How does it work? I see white senerios, which has a link that leads to another board. Then there's IRC-IC. What about the main site? I haven't spawned yet, so I'm not familiar with what it looks like once I get in game. Is the game just for XP and stats and the chat/forums for RP?
Well, technically, RP is everywhere. While flying a fighter for your government, you are RPing as the fighter pilot etc. If you mean written stories etc, the Meeting Hall and the White Scenarios are the places to be.
Generally things happen organically. So rather than the two protagonists saying they will attack and this will happen, one does something in game, and the other then responds. At the end, a story has occured, although it came about organically rather than through people specifically stating that X happens.