What do I need to know before I move to San Francisco?

I'm moving to San Francisco at the end of this year. Can anyone offer me any advice or good sites on housing and/ or jobs? I have a degree in Biology, and a Master's in Indigenous Nations Studies with an emphasis on hydrology, and experience working for a government agency. I would love to work for an NGO or other organization doing water quality work with communities. But honestly, to get out to San Fran I would be a waitress!