Beginning Programming

I have the WPILib file with all the packages installed in Eclipse. How can I actually start programming the robot? I thought I’d use the WPILIb code but when I open each package it doesn’t allow me to edit anything. I’m assuming I shouldn’t be doing this. Can someone please explain to me as to how to actually start programming?

UPDATE: I opened the src file and now I am in the Robot.java class… Should I be here instead?

Go here http://wpilib.screenstepslive.com/s/4485
Click on the language of choice, then look for Creating and Running Robot Programs (or something very close to this)
These links will walk you thru the steps to create a program for your robot