help! I'm lost in DC!

All right, kids, I decided to do it: I would go to DC for Crafty Bastards. I even got Friday off for transit purposes. It looks like I'll be driving up from NC but I am unsure about any other details, like where to stay, where to eat, etc etc. Does anyone have any advice? I'm thinking of staying at a place in the city, but think it might be better if I left my car in Virginia and took the train in, and just bussed and taxied around DC for the duration. Can anyone recommend this? or against it? Also, is anyone else planning to go?