Today, I've just passed the EJB certification and I got 95% ^^
It took me two months of preparation. (Two hours of daily reading and practicing from time to time)
So to resume what I have done to accomplish that.
1- I've started by reading Ivan Krizsan's OCEJBCD 6 study guide it was really a good start
2- After that I've read some chapters on O'Reilly-enterprise_javabeans_3.1_6th_edition(skipped the jpa parts)
3- Then after reading and practicing all the objectives I've began to take test on enthuware(great partner)
4- Lastly after doing all the exams on enthuware I followed it by the leitner mode which is very helpful and a quick reading of Frits Walraven OCEJBCD 6 EJB 3.1 notes
The exam was correct, questions were described in a good way and don't worry about the time you can end the exam and leave a lot of it