California Public Policy and Citizen Participation/Chapter Two
The Brown Act, officially known as the Ralph M. Brown Act, was an act of the California State Legislature, authored by Assemblymember Ralph M. Brown and passed in 1953, that guaranteed the public’s right to attend and participate in meetings of local legislative bodies.
The Brown Act, originally a 686 word statute that has grown substantially over the years, was enacted in response to mounting public concerns over informal, undisclosed meetings held by local elected officials. City councils, county boards, and other local government bodies were avoiding public scrutiny by holding secret "workshops" and "study sessions." The Brown Act solely applies to California city and county government agencies, boards, and councils. The comparable Bagley-Keane Act mandates open meetings for State government agencies.
The introduction to the Brown Act describes its purpose and intent:
In enacting this chapter, the Legislature finds and declares that the public commissions, boards and councils and the other public agencies in this State exist to aid in the conduct of the people's business. It is the intent of the law that their actions be taken openly and that their deliberations be conducted openly. The people of this State do not yield their sovereignty to the agencies which serve them. The people, in delegating authority, do not give their public servants the right to decide what is good for the people to know and what is not good for them to know. The people insist on remaining informed so that they may retain control over the instruments they have created.
A local newspaper opined of the act:
|“||A law to prohibit secret meetings of official bodies, save under the most exceptional circumstances, should not be necessary. Public officers above all other persons should be imbued with the truth that their business is the public’s business and they should be the last to tolerate any attempt to keep the people from being fully informed as to what is going on in official agencies. Unfortunately, however, that is not always the case. Instances are many in which officials have contrived, deliberately and shamefully, to operate in a vacuum of secrecy.||”|
—Sacramento Bee, October 1952
Supporters of the Brown Act say it still lacks enforcement, contending the law has been eroded by court decisions and government officials' efforts to block access to records. "The unfulfilled promise, I'm afraid, that 50 years has revealed, is enforcement," commented Terry Francke, of the California First Amendment Coalition, on the 50th anniversary of the bill's passage in 2003.
- Open meetings are required of all county, city and special districts such as water boards. The Brown Act does not apply to the state legislature itself, to the consternation of some commentators.
- Closed sessions are only allowed for things like labor and real estate negotiations. The body must report back on the progress of closed session at the following open public session.
- Documents at meetings are public, all of them.
- Electronic communications auch as emails must not be allowed to be used to conduct a de facto closed private meeting. Back and forth emails constitute an illegal deliberation.
- Emergency situations allow some exceptions to rules such as the prohibition of back and forth emails between members of a board.
- Public is not required to provide their name or any information when viewing documents.
- Notice of meetings
- No action or discussion shall be undertaken on any item not on the agenda so that the public will have notice, via the agenda, in advance, that the particular action is being taken or discussed.
- Criminal penalties are written into the act if there is proven intent to deprive the public of information, although this is rarely even threatened or discussed.
- Public comment is permitted at all open public meetings but the chair has discretion as to the scope and length of such public comment.
- Public criticism of governemtnt action is allowed but most agencies specifically prohibit personal attacks.
- Recording the proceedings is, by law, permitted, when it is done in a non-disruptive manner.
- Special meetings are subject to all of the same requirements as any other meeting.
The Brown Act applies to "legislative" agencies such as school districts, which "legislate" policy, boards of supervisors, city councils etc.  According to the Primordial Wikipedia Article on the Brown Act,as of the date it was transwiki'd, subcommittees that are less than a quorom do not count. According to that wikipedia article this section was based on, "Advisory committees that do not legislate do not count." However, this writer is on an advisory committee which does not legislate, and Brown Act compliance is enforced very rigorously at all times and, according to city staff, the city could be fined for violating the Brown Act in the conduct of its advisory committee activities. Be sure to consult with the city or county attorney if you are on such a committee or if you are a citizen seeking to enhance the performance of any such committee.
According to the wikipedia article, state agencies are covered by the Bagley Keene Act. 
State agencies are covered by the Bagley-Keene Open meetings act
It is the public policy of this state that public agencies exist to aid in the conduct of the people's business and the proceedings of public agencies be conducted openly so that the public may remain informed. In enacting this article the Legislature finds and declares that it is the intent of the law that actions of state agencies be taken openly and that their deliberation be conducted openly. The people of this state do not yield their sovereignty to the agencies which serve them. The people, in delegating authority, do not give their public servants the right to decide what is good for the people to know and what is not good for them to know. The people insist on remaining informed so that they may retain control over the instruments they have created. This article shall be known and may be cited as the Bagley-Keene Open Meeting Act. 
Notes and references
- Lockyer, Bill (2003), The Brown Act: Open Meetings for Local Legislative Bodies, Foreword, Introduction, and Table of Contents, California Attorney General, http://ag.ca.gov/publications/2003_Intro_BrownAct.pdf, retrieved 2009-06-27
- California Government Code §54960
- Government Code Section 54952
- Search CAL. GOV. CODE § 11120 : California Code - Section 11120
- Lockyer, Bill (2003), The Brown Act: Open Meetings for Local Legislative Bodies, Main Text, California Attorney General, http://ag.ca.gov/publications/2003_Main_BrownAct.pdf, retrieved 2009-06-27
- CFAC.org - 'Ralph M. Brown Act: California Government Code Sections 54950 et seq.'