If you're on your first Android project (like me), get this book, right away! Don't be intimidated by its official designation as "intermediate". As a beginner, you'll want to know how to rescue yourself from bugs. This book provides the context behind every concept: you'll know the why, the what to do next, and the what to avoid (and why!). You'll develop a mental mapping of the "space" where everything sits.
It's aimed at people who've done some Java already, but if you haven't, there's a very nice intro to the Java you'll need (again, with all the vital "why"s behind the "how"s).
Lots of code examples explained step-by-step.
It's intended to be used together with the online Android documentation by Google, but is quite usable all by itself. Its focus on "best practices" is invaluable.