If you are really in the Halloween spirit and ready to be creeped out by a book, I highly recommend Shutter Island by Dennis Lehane. It's a compelling read, suspenseful without causing nightmares, with a great ending.
To boot, Scorcese made a movie based on the novel starring Leonardo DiCaprio, Mark Ruffalo, and Ben Kingsley. It's coming out February 19th. You can watch the trailer here.
Lehane also wrote the novels Mystic River and Gone, Baby, Gone. Both were great movies, but I'm bummed I didn't read the books first, now that I know what Lehane has to offer.
On a side note, don't forget to park your cars in your driveway tonight to lessen the chance that they'll get creamed!