Online Resources: Werewolves. For werewolves, the best place to start is the Werewolf Legends from Germany by Dan Ashliman, along with Sabine Baring-Gould's Book of Werewolves and the Wikipedia article on werewolves.
Online Resources: Vampires. For vampires, the best starting place is the book by Montague Summers: The Vampire, His Kith and Kin (and Summers is a quite fascinating fellow in his own right; you can read more about him at Wikipedia). You might also find the Wikipedia article on vampires helpful. For the classic literary treatments of the vampire, such as Bram Stoker's Dracula, see the Gothic Literature section at Sacred Texts.