From what i currently understand there isn't a emulator/ visual dashboard for the Robot in Java but that would be nice.
I was recommended the Bluej book a few weeks back and I am currently teaching myself how to program in java. I have tried many things so far and found that Bluej offers one of the nicest and best explanations of the java language. It utilizes a book and lessons that are pretty easy to understand. Bluej is just an IDE, most teams use the Netbeans IDE for the competition.
here's the link,
http://www.bluej.org/
i would suggest having them sit down and do it at a pace they can learn at.
if you have any questions feel free to ask