Lifewire

Matt Law's "A Guide to Social Networks" is a comprehensive review of the social networking world.

This webpage as part of a series informative articles on http://www.about.com/ provides a great bulleted and linked overview of this social interactive phenomenon. The linked paragraphs give a short introduction containing basic information on the subject, and links to additional material for investigation on other about.com webpages.

This is the first place I hit before attempting to join a social network.