AstroLinks - Internet's Astronomy Guide: Cosmobrain's Astrolinks is a complete guide for Astronomy on the web. Only selected links.
Astronomy by ExploreSpace.com: Includes an online store, classifieds, telescope information, discussion forum, and astronomy links.
Astronomy Links for Drennon's Science:
Astronomy Resources: Links to hundreds of astronomy sites.
Astronomy World Wide Space Link: Links to largest telescopes, professional astronomers, planetaria, pictures, amateur equipment.
Astronomylinks.com: Over 500 astronomy and space related links, updated frequently. Submit your own link.
Cosmobrain Astronomy and Astrophysics: Helpful index of links relating to many different aspects of Astronomy.
Galactic Surf: Web portal with extensive collection of internet links on astronomy and space topics.
LLEK Bookmarks Scientific Search Engines - Astronomy: A comprehensive catalog of scientific resources and media worldwide but especially in German and English: Directories of Astronomy Journals; Astronomy-related catalogs of scientific search engines; additional starting points and sites of special interest.
Mike Boschat's Astronomy Page: Many astronomical sites.
Sky and Telescope - Internet Resources: Astronomy links, lists and newsgroups.
The Astrobiology Web: An online guide to the origin, evolution, and distribution of life in the Universe as well as all other aspects of space exploration.
The Telson Spur: A Way Station for Snark Hunters: The Snark Hunter's Page is a meta-list of mainly academic resources organized on the theme of necessity vs. contingency in the study of time and evolution.
Top20Astronomy.com: Online directory for astronomy education.