The Monsters Bundle is what October is all about. Bestselling author Kevin J. Anderson has put together a monstrous collection of for this bundle. You want werewolves? Check out Julie Frost's Pack Dynamics and Douglas Smith's The Wolf at the End of the World. Prehistoric monsters? Try Jurassic Dead by David A. Sakmyster and Mammoth Dawn by Kevin J. Anderson and Gregory Benford.
You want occult forces and investigations? We have The Love-Haight Case Files by Jean Rabe and Don Bingle, Working Stiff: The Cases of Dan Shamble, Zombie, P.I. by Kevin J. Anderson, and For This Is Hell by Aaron Rosenberg and Steven Savile. Horrific killers that make Hannibal Lecter look like a lightweight? There's Empty Rooms by Jeffrey J. Mariotte and Helmet Head by Michael A. Baron. Or just plain scary weirdness? Matt Forbeck's Monster Academy, Josh Vogt's Enter the Janitor, and Keith R.A. deCandido's Cayo Hueso. Plus you can choose to donate to The Challenger Learning Center when you grab a bundle!
Basically, pay what you want above a minimum of (I believe) $3, and get six books. Pay $15 or more and get twelve books. There's a FAQ.
It's available for a limited time only, so grab it while you can, sometime in the next three weeks. And please spread the word to folks you think might be interested.