Not all of King's books are horror actually, most people think they are and usually stay away, but he really does have some that are fantastic, and not horror .
Speaking of him though, if you haven't read it yet, I'd recommend The Eyes of the Dragon, def one of his better books, and an easier read for those who don't like his more..uh..gooey books.
Another series that you can read is the Fablehaven books.
My sister didn't really like them, she said they were too childish for her, but I really enjoyed them, and read the first one to my oldest DD, and she finished off the rest on her own. (She's 8, so that gives you an idea of how much of an easy read they are.)