Looking for a great ghoulish story to get you in the Halloween spirit? Try Gothic: Ten Original Dark Tales and especially check out the uber-creepy story, "Watch and Wake" by M.T. Anderson. (M.T. Anderson is always a good read, and you can follow this short story with his fabulous vampire book, Thirsty.)
If you're more into novels than short stories, a new horror book for teens is The Devil's Footsteps by E.E. Richardson. Every kid in town knows the creepy rhyme about the devil's footsteps, and it's rumored that when a kid reaches the last verse, the devil comes to visit. And he's not coming for a nice cup o' tea. Check it out and see what you think.