REALLY need to get into his work. (Despite strangely reading a lot of negative criticism of his work, which is strange as he's a celebrated author. Horror is really not my bag though :L )
Love this quote : "J.K Rowling, now that woman can write. Stephanie Meyer can't write worth a damn."
Some of his later stuff is… not as good as his earlier stuff (Though he is getting back on form).
Just avoid reading Cell and Liseys Story (Had that about 2 years now and i just can't bring myself to finish it, it's so boring).
To be fair to the Naysayers, SK, sometimes, has a lot of trouble ending his books (sometimes they can feel a bit rushed in the last few chapters).
However, its the journey that counts and their almost always pretty damn good (Best example I can think of is his Dark Tower Series. Personally I loved the ending (the only ending of any book I've read that's genuinely horrified me. In a good way) but there are a lot of people who hated it and let that ruin what was a damn good series of books)
Edit: Also If your not that into Horror, try Eyes of the Dragon/The Dark Tower Series (More fantasy like than Horror), Misery (more of a thriller)
or The Stand (post-apocalyptic story. Best thing he's ever done in my opinion) and make sure you read the definitive edition of the Stand