To create Android applications you use Java and the extension libraries that Android provides. These aren't extensions in the Java Language sort of way; I mean libraries that are shipped with Android to help you achieve the common things you'd want to do on a cellphone.
For example, Blackberry (another Java-based mobile OS) uses Java as the language of choice, and Research In Motion provides a set of libraries in the RIM package that helps me abstract things that I'd commonly do on my phone.
You can use pure Java but most of the time you want to use the RIM libraries provided by RIM.
If you're completely new to programming I would recommend first learning good Java principles - classes, methods, object-oriented programming, etc; then learning the Android API provided by Google. If you learn Android first you'll get confused quick and not follow good programming practices.
I recommend starting with the book Head First Java.