This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
Indeed, you can find the information on IntelliJ IDEA features on our Web site. As for JBuilder comparison, we don't have a single comparison document, but I can tell you more about the different feature areas if you could tell me what in particular is of interest for you.
In general, the key distinguishing feature of IntelliJ IDEA is its superior understanding of Java code, which enables a lot of advanced code analysis (inspections) and transformation (refactoring, intention actions etc.) features.
One area where JBuilder is much stronger than IntelliJ IDEA is its UML support.