I'm in DC for the first time and wondering other than the obvious, what are the biggest sites everyone uses to post/shop?

Other than TER boards, I use p411 a lot, and sometimes Eros.  Welcome to DC

I am becoming a big fan of Twitter. It gives you a great opportunity to see what a ladies personality is like through her posts / tweets. It also helps build some report before the meeting and for the lady to get an idea what my personality is like.

TER and Date-Check