USEFUL LINKS
The Astrobiology Web is very extensive and provides links to sites covering all possible aspects of astrobiology.
Additional online resources are provided by:
The NASA Astrobiology Institute
The Extrasolar Planets Encyclopedia provides an excellent summary of our current knowledge of planets around other stars.
The NASA Exoplanet Archive also provides much useful information on exoplanets.
The Planetary Society has as its mission statement "To inspire the people of Earth to explore other worlds and seek other life through education, research, and public participation," and maintains an extensive site with many useful space-related links.