This is not strictly Werewolves only but a site that collects works from the field of Paranormal/Horror in general which are in the Public Domain, most are free downloadeable as PDF's a few require that you sign up.

The stories are among other variations listed by genre e.g. Vampire, Werewolf:
http://horrormasters.com/sub-genre.htm

Given the nature of the site it's naturally mostly classic stuff.
I hope I didn't post this previously already (*blush* really can't remember, the site's around for a awhile).