Werewolf

Graduate Mafia Brotherhood
Lists variants and rule suggestions. Provides a member list, rules, and a game and event history.
http://www.princeton.edu/~mafia/

Loony Labs: Are You A Werewolf?
A commercial release.
http://www.wunderland.com/LooneyLabs/Werewolf/Index.html

Mafia
Provides rules, scoring information, tactics, and a summary.
http://www.stud.ntnu.no/groups/mafia/main.shtml

Werewolf
A summary and game history. Also has links.
http://www.eblong.com/zarf/werewolf.html