Engaging a different way to tackle new technologies

I was trying to get started on JBoss and was reading JBoss's getting started section.
http://docs.jboss.org/jbossas/getting_started/v4/html/

Unfortunately, when I reached chapter 3, it made a reference to J2EE tutorial, http://java.sun.com/j2ee/1.4/docs/tutorial/doc/, in order to gain the backgroud, I start to read this other tutorial, and just like that, I got lost and discouraged in this not very effective learning process. After a bit thinking, I decide to go back the original tutorial, and will continue on it only trying to divert when it is absolutely necessory. I write this to remind myself, even when I am doing something not under a deadline and totally for my own interests, I have to learn to ignore the depth initially and try to get my hand on only small managible sizes. Reduce the size and my own expectation on area that requires attentions.