Locate the California code section you are researching, then find and note the session law chapter numbers, given at the end of the code section. An example is "Added by Stats.1978 c. 458 1," which means the statute first appeared in Statutes and Amendments to the Code 1978, chapter 458, section 1.
West’s Annotated California Codes ( KFC30.5W4 - 4th Floor Research Alcove and Deering’s California Codes Annotated ( KFC30.5 D4 - 4th Research Alcove) provide the current version of the law, a list of all of the amendments to the law, and the session law chapter numbers. (E.g. Added Stats. 1978 c. 458 1. Amended Stats 1984 c. 334 1). The annotated codes may also provide references to interim hearings, committee reports, legislative counsel opinions, law revision commission reports, attorney general opinions, the California Code of Regulations, law review articles, and notes of court decisions.
Be sure to check the pocket part or pamphlet for the most recent amendments, law review articles, court decisions, and other legislative history.
Note: West’s Annotated California Codes includes the bill number after the text of the code section, for laws passed after 1994 (E.g. Added by Stats. 1997, c. 852 (AB 1191), § 4). AB stands for Assembly Bill; if your example lists (S 392), then S stands for Senate.
To begin a legislative history on a code section that is not current, UC Hastings has print collection of historical code volumes from several publishers available on the 5th floor at KFC 30.5. The Library also has a historical collection of Deering's California Codes and pocket parts from 1866-2000 on the 5th Floor at KFC30.5 .D4 These volumes are an invaluable tool to find the law exactly as codified in any particular year.