The official site for Android developers. Provides the Android SDK and documentation for app developers and designers.
FREE online ebook: Learn Version Control with Git
Learn Version Control with Git, A step-by-step course for the complete beginner. The goal of this book is to get you started with version control and Git as quickly and easily as possible. It's aimed at beginners of programming, at designers, at project managers... It tries not to require too much prior knowledge on the technical side. It tries to go slowly.