City and County of San Francisco - Official City Homepage
Here is a sampling of some of the departments and the reports available:
San Francisco Public Library - Government Information Center. This is an excellent resource for finding city government information.
Healthy Development Measurement Tool A place to find a lot of interesting neighborhood data, broken down by neighborhood. Very easy to use!
San Francisco Property Information Map use this to retrieve data on specific properties
CrimeMapping.com find data on crime in the vicinity of any San Francisco address.
San Francisco Community Services Directory brought to you by the San Francisco Public Library (Please note that this directory is maintained for historical reference only. No records have been updated since March 2009.)
San Francisco History Center part of the San Francisco Public Library. The Center is also the official archives for the City and County of San Francisco.
San Francisco Unified School District
SFGate Data Center
Association of Bay Area Governments
Metropolitan Transportation Commission
Bay Area Census Data