I don't know the percentage of J2EE those technologies comprise, but at least I can point you in the direction of a good (in my opinion) and free tutorial. Sun has a downloadable J2EE tutorial that has examples of all J2EE technologies. I believe it's a pdf, too.
Let me know if you have trouble finding it and I'll post a link.
Give a man a fish, he'll eat for one day. Teach a man to fish, he'll drink all your beer.
Cheers, Jeff (SCJP 1.4, SCJD in progress, if you can call that progress...)