How do I use eclipse to compile?

First install Oracle’s (formerly Sun’s) Java JDK and the Java Runtime Environment, then install Eclipse. Then make sure the Android SDK is updated.

Google provides their SDK and the Eclipse IDE in a single preconfigured download. At the time of writing this it can be found at http://developer.android.com/sdk/index.html

This is where you can start to learn to use the tool http://developer.android.com/training/basics/firstapp/index.html

The necroscope says "google search and youtube is your friend when you want to learn eclipse"