There's always the "Twilight" series if bad writing horrifies you.
Otherwise, try H.P. Lovecraft. I'd also recommend his biography - he had an interesting life.
Not exactly in the horror genre, but read Ambrose Bierce's civil war stories. "An Occurrence at Owl Creek Bridge" ought to get you hooked. Bierce actually served and was injured in the Civil War - his perspective was unique. Like Lovecraft, read up on his interesting life and possible death. I like to think he's still alive and wandering the southwest.
There are tales about a ghostly old gringo in the desert around here. It must be Bierce.
Another great writer that should interest you is Philip K. Dick. Not strictly horror, but good enough to be on any recommended reading list. The five volumes of his short stories are well worth buying.
If you don't mind me recommending yet another quasi-horror author, try T. Coraghessan Boyle's short stories. "Greasy Lake" is a real favorite. Still another favorite author in the same vein is Roald Dahl. Yeah, he's known for kids' books. But try his - rather - adult short stories. You won't read them to your children, trust me. But they're a hell of a lot of fun.
Oh, and pick up Evelyn Waugh's "The Loved One." Not horror, but incredibly dark. And very, very funny.