Ebook: Sams Teach Yourself Android Application Development in 24 Hours (Sams Teach Yourself -- Hours)

This is a good book for the beginning Android developer who already has experience developing in Java. A lot of the basics are explained in an easy to understand example-driven way. Because this book is in full-colour with a lot of screenshots it is easy to read.
A seasoned Android developer could use this book as a reference book, although there are probably books better suited for the seasoned developer.