Ok, I actually finished reading Coraline two days ago. I've been kind of busy with some other things, and I haven't gotten around to posting (You'll probably hear about those other things in a few weeks).
Anyway Coraline is a great book, which isn't all that surprising as it's written by Neil Gaiman and has illustrations by Dave McKean. It's one of the creepiest books I've ever read, and despite being written for children--and being very short--it's really terrific.
The book is about a girl named Coraline who finds a mysterious door in her parent's flat (that's an apartment to us Americans).
This door leads to a strange world inhabited by weird version of Coraline's family and neighbors. The place was created by her Other Mother who is really a malevolent being that wants to eat Coraline's soul (or something). Coraline has to use her wits to defeat the fiend, rescue her family, and escape.
It's a really great book, though I would hesitate to read it to very young children, as it just might give them nightmares. I give Coraline 5 yo-yos.