This is my favorite book, and it explains EVERYTHING in a way that both experienced rattie owners and new rat owners can understand. The title sounds like a children's book, but is full color, and is actually explained in an adult manner but I think even the youngest rat lover could understand it.
My Rat by Gerd Ludwig
Some inside photos
I love the "did you know?" facts as well.
This book isrobably the best down- to-earth book and should be a first choice. It's well worth the money and I recommend it to be in a rat owner's "library!"
Next, this book is slightly more from a higher level, but it is pretty helpful - just lacks the feature of being both detailed and really easy to understand for first time rat owners.
RATS - Practical Advice from the Expert
By Debbie Ducommun