Astronomical League
The parent organization of many astronomy clubs in America. The site includes details of the Leagues observing programs, such as; The Messier Club, The Herschel 400 Club, etc.

International Dark Sky Association
Information on lighting ordinances and legislation/efforts to reduce light pollution at astronomical observing sites.

Southern Cross Astronomical Society
Founded in 1922 in Miami, Forida, the SCAS hosts the now famous "Winter Star Party." Site includes information about the star party.