You're welcome. :) I remember myself that it was really weird figuring how to approach this sort of thing - it's not like it's written in the Gamemaster's Manual or Player's Handbook. Trying to find the right sort of games and such isn't always straight forward.
After figuring out what the tone of the game is, you should probably figure out what sort of commitment you want from a game. A long term game that's a lot like writing a series of books/playing a traditional RPG game that lasts basically indefinitely, a short term game that's not really going to last after the given story, a scenario or series of scenarios that really don't involve the inbetween (or the inbetweens don't matter). Different games will emphasize different sorts of commitment and will offer different things. While long term games may offer the best chances of really deep development, like in most things, not all of these games will last nearly long enough to accomplish something. Shorter games may do more things but you may find you want more meaningful things to do. Relatedly is whether the game is run more as a collaborative story, GM/player, or a communal game (freeform, basically). Depending on what the point is, the plot and the pacing may or may not be directed. You may prefer a more story oriented format over a game oriented one; you may prefer the more focused but limited small/solo interaction or may prefer a more open ended many player format.
Also, and this is really a personal caveat, is to figure out how you are personally approaching this stuff. Are you an actor playing a role or a writer writing a character? The sort of investment and writing style each of those two approaches involves varies. You may prefer players who have a more direct 'acting' posting style but on the flip side, you may get into trouble by becoming too personally invested.
On a minor point, you may want to figure out how graphic or mature you're comfortable with and what will satisfy you. That is, language (both in use and description), how things are phrased, and so forth. You may want something more explicit ("He thrusted his - - - into her furiously - - - as she screamed 'bleep me!' and squirted blah blah blah") or you may want something that is more prose based ("She fell atop of him as the orgasm overwhelmed her blah blah blah") - this not just being the sex but related details; seems like it tends to be a trade off between raw erotic energy versus sensual romanticism though your mileage may vary.
Anyway, all that should help you get a fairly focused idea of what you're looking for - you'll probably figure out other stuff along the way.
Oh, and since you already have some sort of idea for the character opposite yours, figure out what you're looking to get out of them is good too if you're really picky so your partner knows whether you're looking for Vin Diesel, Sean Connery, or whatever. If you're not, then less of an issue.