Digital Atlas of California (California Geographical Survey) Contains demographic and social maps for the entire state and major metropolitan areas.
Home Affordability in California's Counties (Public Policy Institute of California) Interactive map shows change in median home values, percentage of homeownership rates and owner costs that are 30% or more of household income for each California county in 2000 and 2006.
Population History Maps of California Places, 1770 to 2000 (Berlo) 2000 (ref HB 3525 C2 B471 2000) Consists of approximately 1,000 maps that show the location and size of populated places in California at 10-year intervals from 1770 through 2000. A companion work is Population History of California Places (Berlo) 2000 (ref HB 3525 C2 B47 2000) that includes population figures for California places at 10-year intervals from 1846 to 2000; yearly intervals for early California places 1769 to 1850; and other population tables. Also includes a set of 50 maps showing all included place names.
Zip Codes by County: California (Melissa Data) Includes by county a Google Maps outline of each zip code, along with a table giving demographic and economic characteristics of the zip code. Requires free registration.