The Commonwealth of Nations was originally the British Commonwealth and consists of 53 member states, most of which were once part of the British Empire. Their goals are outlined in the Singapore Declaration and include promotion of democracy and human rights and world peace.
Regular Websites
About.com: Commonwealth of Nations
Detailed article about the history of the organization with links to similar articles on About.com. - About.com: Commonwealth of Nations
http://geography.about.com/od/politicalgeography/a/commonwealth.htm
Extensive site provides information about the Commonwealth itself, the member states, the Secretary-General, and various Divisions and units. Further details include the timeline of the organization, videos about items of interest, and blogs. - Commonwealth Secretariat
http://www.thecommonwealth.org/
Consists of information about the Commonwealth, its members, and beliefs as well as a yearbook of members. - The Commonwealth
http://www.commonwealth-of-nations.org/