Welcome to Training for Android developers. Here you'll find training classes that describe how to accomplish a specific task with code samples you can re-use in your app. Classes are organized into several groups you can see at the top-level of the left navigation.
The first training guides below teach you the essentials for Android app development. If you're a new Android app developer, you should complete each of these classes in order.
Various online video courses are also available if you'd prefer an interactive video experience.
Check out this trailer for a course about the fundamentals of Android development on Udacity.