Hi yes the main problem is that there is no dedicated book for the SCBCD so i read the exam Objectives and focused on the objectives during my studies, I used the following books to study for the exam:
1) Manning: EJB3 in action
2) O'Reilly: Enterprise
Java Beans 3
3) Pro EJB3
and i read the review notes after i finished reading the books.
in addition i used enthuware exam simulator for mock ups. I was scared of XML mappings however it seems that a basic knowledge of them is enough.