Overview of Legislative Process
Source: California Legislative Information; http://www.leginfo.ca.gov/bil2lawx.html
The process of government by which bills are considered and laws enacted is commonly referred to as the Legislative Process. The California State Legislature is made up of two houses: the Senate and the Assembly. There are 40 Senators and 80 Assembly Members representing the people of the State of California. The Legislature has a legislative calendar containing important dates of activities during its two-year session. 
Idea
All legislation begins as an idea or concept. Ideas and concepts can come from a variety of sources. The process begins when a Senator or Assembly Member decides to author a bill. 
The Author 
A Legislator sends the idea for the bill to the Legislative Counsel where it is drafted into the actual bill. The draft of the bill is returned to the Legislator for introduction. If the author is a Senator, the bill is introduced in the Senate. If the author is an Assembly Member, the bill is introduced in the Assembly. 
First Reading/Introduction
A bill is introduced or read the first time when the bill number, the name of the author, and the descriptive title of the bill is read on the floor of the house. The bill is then sent to the Office of State Printing. No bill may be acted upon until 30 days has passed from the date of its introduction. 
Committee Hearings
The bill then goes to the Rules Committee of the house of origin where it is assigned to the appropriate policy committee for its first hearing. Bills are assigned to policy committees according to subject area of the bill. For example, a Senate bill dealing with health care facilities would first be assigned to the Senate Health and Human Services Committee for policy review. Bills that require the expenditure of funds must also be heard in the fiscal committees: Senate Appropriations or Assembly Appropriations. Each house has a number of policy committees and a fiscal committee. Each committee is made up of a specified number of Senators or Assembly Members. 
During the committee hearing the author presents the bill to the committee and testimony can be heard in support of or opposition to the bill. The committee then votes by passing the bill, passing the bill as amended, or defeating the bill. Bills can be amended several times. Letters of support or opposition are important and should be mailed to the author and committee members before the bill is scheduled to be heard in committee. It takes a majority vote of the full committee membership for a bill to be passed by the committee. 
Each house maintains a schedule of legislative committee hearings. Prior to a bill's hearing, a bill analysis is prepared that explains current law, what the bill is intended to do, and some background information. Typically the analysis also lists organizations that support or oppose the bill. 
Second and Third Reading
Bills passed by committees are read a second time on the floor in the house of origin and then assigned to third reading. Bill analyses are also prepared prior to third reading. When a bill is read the third time it is explained by the author, discussed by the Members and voted on by a roll call vote. Bills that require an appropriation or that take effect immediately, generally require 27 votes in the Senate and 54 votes in the Assembly to be passed. Other bills generally require 21 votes in the Senate and 41 votes in the Assembly. If a bill is defeated, the Member may seek reconsideration and another vote. 
Repeat Process in other House
Once the bill has been approved by the house of origin it proceeds to the other house where the procedure is repeated. 
Resolution of Differences
If a bill is amended in the second house, it must go back to the house of origin for concurrence, which is agreement on the amendments. If agreement cannot be reached, the bill is referred to a two house conference committee to resolve differences. Three members of the committee are from the Senate and three are from the Assembly. If a compromise is reached, the bill is returned to both houses for a vote. 
Governor
If both houses approve a bill, it then goes to the Governor. The Governor has three choices. The Governor can sign the bill into law, allow it to become law without his or her signature, or veto it. A governor's veto can be overridden by a two thirds vote in both houses. Most bills go into effect on the first day of January of the next year. Urgency measures take effect immediately after they are signed or allowed to become law without signature. 
California Law
Bills that are passed by the Legislature and approved by the Governor are assigned a chapter number by the Secretary of State. These Chaptered Bills (also referred to as Statutes of the year they were enacted) then become part of the California Codes. The California Codes are a comprehensive collection of laws grouped by subject matter. 
The California Constitution sets forth the fundamental laws by which the State of California is governed. All amendments to the Constitution come about as a result of constitutional amendments presented to the people for their approval.