Accommodations
Wiki Travel has a great page on San Francisco including recommendations for places to stay. This Organizer's strong personal recommendation is Green Tortise - get a room as high up as possible and book early as they will fill long before the conference.
Also, check the OSNCon/Couches to see if any kind San Franciscans have offered up their couch space.
Transportation Directions
Campus Map if you drive, park at park at the parking structure at F-5 (those are coordinates on the map). Our building is marked as "C. Chavez Student Center". The main conference room is in "Jack Adams Hall" on the top floor.
Directions to Campus Information for those planning to drive, walk, bike, or (my favorite) take public transportation.