I just finished reading Merle's Door by Ted Kerasote. It's a true story about a dog named Merle, who was found as a stray and rescued by the author. The author lived in a very small rural community and decided to install a doggie door to give Merle his freedom, hence the title.
While I don't agree with everything in the book (letting dogs roam, 1 instance of shock collar use, 1 of choke collar) I found it an enjoyable read, and you could tell the author really cared for Merle. For anyone who enjoys books about real dogs, this one is probably worth a look.