Arnie Cunnigham and his new/old car named Christine are the main characters of the book, along with Arnie's best friend Dennis. Dennis was with Arnie the day that he bought Christine from Roland D. Leby. From that day, Dennis knew that buying that car was the worst thing Arnie had ever done.
Arnie changed in many ways after he bought the car. He started getting in fights with his parents. He even got in a fight at school, getting the kid expelled. He had a really bad complexion before he bought the car. Dennis noticed that Arnie's acne was starting to go away, so he complemented him on it by saying a joke. Arnie didn't like the joke very much at all. Arnie even got his first girl friend. All the guys at school couldn't believe she would go out with a dork like him.
All of sudden everyone who had made Arnie upset at one point start dying. All the police know is that a red car was involved and that these people have at one point gotten on Arnie's bad side.
This is one of the better horror stories I've read, and I read a lot of horror novels as you can tell. Stephen King takes the classic American scenario, a boy and his car, and warps it into a horror story. The plot is much better than what you would think of it (yay, a psycho car.. scary!). Although it gets a little stretched out in the middle, it's pretty consistent in the story telling.
The characters in Christine are real people, they're the kind of people you know in real life. So that's what is another thing that makes this story so good. You can imagine it happening to you or your friends.
The only complaint I have is that it is inconsistent in the story telling. For two thirds of the book, it is written in first person, while in the middle it's not. If Mr. King kept on the style of first person it would make this book great.