Other
Astronomylinks
This is a very comprehensive site on the subject of Astronomy and Astrophysics. The site has links to many sites on topics including astronauts, astronomy, astrophysics, education, jobs, etc.
Wikimedia
Wikipedia: The Black Hole
This site examines the black hole as an object in astrophysics. Delve into this comprehensive resource that covers this concept from its history, to qualitative physics, the reality of black holes, mathematical physics and more.