California Department of Real Estate (DRE) provides info on licensees
Did you know that you can look up the license status of a realtor? Simply go here: http://www2.dre.ca.gov/PublicASP/pplinfo.asp
and you can locate the license information for any realtor.
Why would you want to do this? The DRE records will shows how long the realtor has had the license, and if there are any disciplinary actions against the realtor. You might want to verify this information before selecting a realtor.
By the way, the DRE website (http://www.dre.ca.gov/) has a lot of information online, including the real estate Reference Book.