Android

Android runs on hundreds of millions of handheld devices around the world, and it now supports these exciting, new form-factors.
Site: http://developer.android.com

Books

Added Agile Android Software Development

This book teaches you how to turn your ideas into successful apps that everyone will talk about, love, and share. With Agile tools and techniques, any developer can get a chunk of the Android pie!

 Free book

Added Android Programming Succinctly

Navigate the key requirements for designing an Android application with Android Programming Succinctly as your guide.

 Free book