I gave this three stars, because I personally wanted to give it two, but I think it probably deserves four. I know that for other people, especially the audience it's actually intended for (children/YA), it would be a great book, and they'd love it. I didn't really get into the book, and it's not the author's fault at all. It was just too easy a book for me to really enjoy. The bad guy was really bad, the good guys were really good, and even the character who switched sides made all the right decisions when the time came, and no one seriously held his past evils against him.
It's not that the characters were flat--well, maybe some of the secondary characters were--it was just that it wasn't what I was looking for. One of the problems was that I read books (and watch tv and movies) for the characters. Their emotions. The ways they interact with each other. I found a lack of emotional intensity between the characters in this book. It was evident that the characters had emotions toward each other, but even when one of them was in a dangerous situation, there was no urgency, no heart-pounding terror, from the other characters.
So, anyway, it's a fantasy novel about a dragon, his magical-creature companions, and a boy, who are searching for the "Rim of Heaven" in hopes that other dragons will be living there (because the, uh, herd? of dragons that Firedrake currently lives with are about to be washed out by humans who want to flood their valley), safely under the radar of humans. Not for me, but I would recommend it for children/YA.