You know Java and you are looking for a simple introduction how to start with Java EE - try Java EE 5 - Development with NetBeans 6 from David R. Heffelfinger.
What I find most intriguing about the book is the coupling between something known to be complex and heavyweight (not really anymore if you believe Adam Bien) and something quite simple to use. The book shows the ease of doing Java EE development with NetBeans IDE - and I have to admit (as a long time NetBeans user) it really is easy to use. To give a short overview I would just say that all the buzzwords are covered (JSF, JSTL, JPA, WS, ...). But do not expect a reference book for Java EE 5 - it really is a hands-on one getting you to do something so you will be comfortable with the more complex Java EE things.
You want to know more details - listen to the NetBeans Podcast which has an interview with David up on its current episode.
Give it a try!