USNO PMM Star Catalogs - USNO is making the USNO-SA2.0 catalog (54,787,624 stars in all on one CD-ROM) available for free. The full USNO-A2.0 catalog (526,230,881 stars on 10 CD-ROMs) is also available provided you can provide a brief explanation of why USNO-SA2.0 is not sufficient. That's information on over half a billion stars!
The Hipparcos Space Astrometry Mission - home page, site guide, research tools, news and results, the catalogues, education, visual results, further information, the future, animations.
The Hipparcos CatalogueGSC - The Online HST Guide Star CatalogueWhite Dwarf Database - An electronic database of the white dwarf stars.
The Galactic Gazetteer - Database of 13000 nearby stars, viewable using Stellavision 3D Java applet.
The 50 Nearest Stars - Table with details about the 50 nearest stars. Names, distances, constellations, spectral types, magnitudes and coordinates.
The Double Star Library - The Double Star Library hopes to be a means by which various types of binary and multiple star information can be easily disseminated among binary star astronomers in IAU Commission 26 and related commissions.
Catalog of White Dwarf Stars McCook and Sion - A catalog of spectroscopically identified white dwarf stars, by George P. McCook and Edward M. Sion