Before preparing for the exam , I had coded few stateless session beans, but since the framework was already in place , I had absolutely no idea about EJB. I read the HFEJB book and just about everything was new to me.
Since I got interested in the subject I could easily spend 2-3 hrs day with the book (Couldnt afford more given the work hours). Completed reading the book twice in 25 days. Then followed it up with MZ's notes. Read it twice before taking the HFEJB mock test
( where I scored 85%) and once after it.
I also gave the section-wise EJBCertficate exam and identified my weak areas. I dint give the full length mock exam though.(Fear of a low score may be! ) and thats it! Was brave enuf to give the test and concentrated really hard during the exam and managed to score 90%
The exam was fairly simple and straight forward. If you have the time , it will be worth going through the spec for security.
It will also help to learn to write flawless EJB-QL queries.
Hope this helps!