This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
I have just passed the jpa certified with score 83%
To prepare I used only few sources
1. book "Pro JPA 2:Mastering the Java Persistence API" In my opinion this book is better then JPA specification
2. tests: Enthuware's exams (harder than real exam )
There are very useful and good enough to pass exam
3. EJB 3.1 specification - only few pages (about exception handling)
4. JPA specification - I read it when I didn't understand question explanation provided by Enthuware's