All right, so, I admit I read this book a few years ago. I remember it very well, which I think gives the book some points, and allows me to review it accurately...so, here goes.
Dragon Rider seems like a really good book for children who are begging for fantasy and/or dragons. Firedrake, despite his deplorable name, is actually a wonderful character. Ben was okay; Sorrel was also a good character, although I didn't like her personally. I loved that the dragons feed off of moonlight.....but I loathed the rats and everything to do with them.
I think it was the coincidences in this book that really killed it for me--that's why I'll probably never read it again. I won't go into detail, but if you read the book you'll know what I mean. I was eleven when I read it, so I didn't notice so much, but time passed and I read more and more, and gained enough objectivity to tell that it's truly ridiculous.
Dragon Rider is maybe not a great book, but it' an enjoyable one for the most part, and it's harmless.