Alex Barret and Stuart Clark, Secret Worlds: Black Holes . London: Dorling Kindersley, 2002. An up-to-date overview of the subject with many colorful illustrations.
Heather Couper and Nigel Henbest, Black Holes . London: Dorling Kindersley, 1996. A handsomely illustrated book that explains the basic concepts surrounding black holes in easy terms for young people. Highly recommended.
Nigel Henbest, DK Space Encyclopedia . London: Dorling Kindersley, 1999. This beautifully mounted and critically acclaimed book is the best general source available for grade school readers about the wonders of space. Older readers will find it useful, too.
Patrick Moore, Astronomy Encyclopedia . New York: Oxford University Press, 2002. This handsomely illustrated book contains hundreds of short articles about all aspects of the stars, planets, and other celestial bodies, including white dwarfs, neutron stars, and black holes.
Chris Oxlade, The Mystery of Black Holes . Crystal Lake, IL: Heineman Library, 1999. One of the better books about black holes written for young readers.
Paul P. Sipiera, Black Holes . Danbury, CT: Childrens Press, 1997. A commendable general overview of the subject with some attractive illustrations.
"Black Holes," Cambridge Relativity, 1996. www.damtp.cam.ac.uk. A general overview of black holes, with many stunning color photos and diagrams.
"NASA Spacelink," NASA. http://spacelink.nasa.gov. This leads to an excellent site about black holes, with numerous links to other sites explaining different aspects of the subject. Highly recommended.
Robert Nemiroff, "Virtual Trips to Black Holes and Neutron Stars," NASA. http://antwrp.gsfc.nasa.gov. A series of excellent, accurate graphics allow viewers to approach, circle, and at times even land on black holes and neutron stars. Also has links to pages with background information.