How about right on their site, to start? http://developer.android.com/training/index.html http://developer.android.com/training/index.html Edit to add that ap

How about right on their site, to start? http://developer.android.com/training/index.html http://developer.android.com/training/index.html Edit to add that applications are usually developed in the Java programming language using the Android Software Development Kit, but other development tools are available.