MarsDaily : A daily digest of Mars news compiled by SpaceDaily.com. www.space.com - A popular Mars and Space related news site.
The Planetary Society : One of the largest public Space interest groups, supports the policy that the manned exploration of Mars should be the next and the primary goal of human space exploration.
The Mars Academy : An educational site that gives a good foundation on the hows and whats of space exploration.
National Space Society : National Space Society promotes exploration of both Moon and Mars.
President's Commission on Implementation of U.S. Space Exploration Policy : President George Bush annouced in early 2004, that the next goal for the manned exploration of space should focus on Mars, with Moon to be used to facilitate the development and testing of technology and processes meant for Mars.
JPL's Mission Archive : A listing of NASA-JPL missions to Mars, from Mariner to present.
Planet MARS Home Page : Focuses on how to make settlement on Mars a reality. Read papers on the subject, preview the Mars rocket, spinoff products to pay for the project, and see photos from a landing site.
European Space Agency: Mars Express : The European Space Agency's MarsExpress mission to Mars is in orbit around Mars right now !