I came across the National Association of Corporate Directors
website that contains a good summary of some generally accepted governance guidelines (GAGG?) put out by several different organizations.
Jokes aside, this is a good go-to site for looking up relevant rules and guidelines. Here's a list:
Corporate Governance Codes and Practices in the New Era of Corporate Accountability
Sarbanes-Oxley Act of 2002 (PDF, 130 pages, 680Kb)
Sarbanes-Oxley Act of 2002 Imposes New Rules for Corporate Governance and Reporting (Weil, Gotshal & Manges LLP. - September 2002)
New York Stock Exchange (NYSE) -- Filing of Proposed Rule Change and Amendment -- http://www.sec.gov/rules/sro/34-47672.htm
NASDAQ - Summary of proposed corporate governance reforms -- http://www.nasdaq.com/about/Web_Corp_Gov_Summary%20Feb-revised.pdf
AMEX - Enhanced Corporate Governance and proposed rule changes --http://www.amex.com/?href=/atamex/news/am_corgov.htm
National Association of Corporate Directors (NACD) - Recommendations for Reform post-Enron
Organisation for Economic Cooperation & Development (OECD) - OECD Principles of Corporate Governance (PDF, 42 pages)
The Business Roundtable (BRT) - Principles of Corporate Governance (PDF, 37 pages)
Council of Institutional Investors (CII) - Corporate Governance Policies
TIAA-CREF Policy Statement on Corporate Governance - http://www4.tiaa-cref.org/libra/governance/index.html
CalPERS Governance Principles -- http://www.calpers-governance.org/principles/default.asp
The World Bank - Corporate Governance Principles of Best Practices -- http://www.worldbank.org/html/fpd/privatesector/cg/codes.htm
Comparison of Corporate Governance Guidelines and Codes of Best Practice: United States - Source: Weil Gotshal and Manges, 2003