Very short. Very enjoyable. Read it before you see the movie. I've seen the movie a few times (it's great!) and it detracted from the reading experience a little bit.

The book is filled with things that signal "creepy": a big old mysterious house, a secret passageway that comes and goes, a door that should stay locked, eccentric neighbors who give cryptic advice, a black cat. And then, signals in place, we enter the realm of the truly sinister: a mirror world that's just a little off, where the eccentric neighbors and Coraline's father have buttons sewn over their eyes, and the black cat can talk but isn't terribly informative. The skittering heart of the mirror world is the "other mother", a mysterious creature who just wants to love Coraline like she deserves. But, like everything else in mirror world, she's not a perfect copy of Coraline's real mother: her fingers are too long, her hair moves too independently, and the skeletons in her closet are literal. She is Not Nice.

It's a fun story and all the creepy set pieces are there, but I wasn't particularly creeped out, and that's why I think seeing the movie first is a mistake, especially in this case. The book is so short (which is fine, it's a kids book after all) that the cast is necessarily small, there's no subplot, and the main plot is paced quickly without a lot of steps between page 1 and the end. There's not a lot to work with from a film perspective, so the film grew it a little bit--made the mirror world occupy a bigger physical space, added a character, gave the eccentric neighbors more to do, and in so doing created a more complex world with subplots. There's almost nothing in the book that isn't in the movie (one short scene and a blink-and-you'll-miss-it detail about one of the stolen children), which meant no surprises as I read, which in turn ruined the creep factor for me.

But it's a good enough book that it would have been deliciously creepy under different circumstances. Just don't watch the movie first.