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That's strange, I did post a reply, but it doesn't seem to be showing up. /shrug
Anway, most of the rules on playing the game can be found in the SRD. It'll tell you how to make a character, rules for combat, skills, feats, monsters, etc. To play a game you'll need a setting, which the DM can either make himself, or buy in a book. My advice is BE PATIENT. PbP games take a really long time to go through. A single session in real life could easily take a month or longer over a message board.