1)You need to have this book :-
Head First EJB by Kathy Sierra and Bert Bates.
2)You can also refer the specs from :- http://java.sun.com/products/ejb/docs.html#specs
Please read the EJB 2.0 specs.
3)You can also buy the whizlab exam simulator.
4)You can also refer Mastering EJB second edition by ED Roman.
Mind you the first point is compulsion for passing. All the best.