What books and resources are recommended for a designer who wants to pick up android design?
I started here: https://developer.android.com/design/patterns/index.html
And I also worked with some developers who were pretty passionate and knowledgable about Android. Try to work with people like that, or talk to people who use Android to get an idea of how much you don't know about how it works in comparison to iOS (if that's what you're used to)
I would look at this AFTER you look at the "old" documentation I linked to above, because the old stuff is foundational: http://www.google.com/design/spec/material-design/introduction.html
Try Pro Android UI http://www.amazon.com/Pro-Android-UI-Wallace-Jackson/dp/1430249862