Hi
A good book to get started is Head First EJB, although it is often wise to gain some experience before jumping into the exam. I thought about taking the exam a while back when I had no EJB experience but then I considered the fact that I would have the certification but still no experience, and this would not make me more employable.
Good luck anyone. The HEAD FIRST book is a really good read for those with little or no exposure to EJB but with a reasonable understanding of
Java.
Cheers
Mark