I wouldn't ordinarily do this, but I am currently reading Android Application Security Essentials by Pragati Ogal Rai and published by PackT Publishing.
(you can check out the book here: http://bit.ly/15mnEus)
Seeing as how more and more people are moving the mobile devices (smartphone and tablets) not just as a secondary device but sometimes a primary device, security applications on these devices becomes more and more important. This book aims to address it. I am still reading it, but what I've read it pretty good. Even if your focus is not application development, this will help your understanding of Android security.
Once complete, I hope to do a full review here. In the meantime, check out the publishers other works. I've seen several that have caught my eye.