DCH House Rules

New rules for Third Edition campaigns.
http://home.earthlink.net/~chlj/DCH3rules.html

The Unofficial DC Heroes JLA Source Page

Features character descriptions from the Grant Morrison/Howard Porter era of the Justice League. Also includes a gallery and a map of the Watchtower.
http://www.geocities.com/Hollywood/Set/4398/jla.html

Writeups.org

Searchable detailed writeups of characters from all media--comics, movies, tv shows, and other games.
http://www.writeups.org/

AlertForce

Campaign history, with hand-drawn character portraits and maps. Also includes character sheets and adventure summaries.
http://www.nauticom.net/www/racerx/afgal.htm

More Action Fun

Golden Age campaign set in 1932. Includes background, characters, and conversion notes for Champions and GURPS.
http://members.tripod.com/~Lunaseas/Morefun/hq.html