Here's some links to sites I've found useful... I'll post more up over the coming holiday break!
Horror.net - Great link site and resource for all things horror!
VISUALDARKNESS® :: The Artwork of MIKE HRUBOVCAK -Here's an interesting find.... if you like your art bloody, disgusting and morbid with some strong occult overtones this is for you. This guy is pure talent and the technical proficiency with which he creates is nothing short of amazing. He's done some high profile cover art for bands like "Six Feet Under" and "Sinister" and even finds time to sing for American death metal band "Monstrosity"