I am a northern VA native who spent 4 1/2 years working in SF before coming back to DC 2 years ago. this site http://www.san-francisco-travel-secrets.com/san-francisco-neighborhoods.html has a pretty accurate quick glance at the different neighborhoods. But based on where you live in DC, and where you will be working in SF, I’d suggest Russian Hill, Filmore/J-Town, or Hayes Valley. russian hill has a good number of east coast transplants (thats where I lived, and i also worked near union square, very easy 20 minute bus ride to work) and I really liked that neighborhood. filmore/J-town and hayes valley are also very nice. the marina has a good number of LA and NYC transplants, with their usual style of partying/douchbaggery. which, for full disclosure, i did sometimes partake in. the tenderloin is very rough, dont suggest you live there. lotsa drugs and prostitution, and drunk/high guys peeing on the street. from between cars. into the street. the mission is super hipster allstars, but still a pretty neat spot.The richmond and sunset would be a fairly long 30-40 minute bus/train commute.
i loved SF, make the most of your time out there, and enjoy all there is to do and see.
also, if you are a skins fan, there is a great skins bar on Bay at Stockton called the Red Jack Saloon. was a great way to tie me back to the area. and to start drinking at 10am on sundays.