I am reading What the Dog Knows, by Cat Warren. It is a fascinating story about a German Shepherd, trained as a cadaver dog.. Sounds a bit gruesome, but actually completely gripping. I got the book because I was looking for information about scent and hunting/scenting dogs, and this came up on the amazon search. I am completely hooked!
It has a lot of general information, and is an easy read. I also got a very specific book about scenting information, Scent and the Scenting Dog by William Syrotuck, which is a lot more specific and scientific.