It's kinda difficult to give you a hierarchy of topics. The certification give you a list of objectives. I would recommend you to go objective by objective (just like Mikalai Zaikin notes do).
Mikalai Zaikin Notes Its also very helpful to read about the experiences of people that already passed the
test.
Wall of Fame Anyway, the following is a VERY VERY little list of topics that should help you to start studying:
1- Enterprise JavaBeans: Session Beans (Stateless, Stateful) - Message-Driven Beans. (They are components, they can not live outside of the container)
2- JPA (Object-Relational mapping): Entity Beans (They are POJO's, they can live outside of the container). Entity Beans lifecycle management: Entity Managers, Persistence Contexts (Transaction-scope, Extended).
3- Interceptors.
4- Transactions.
5- Exception handling.
6- Security.
This is just like an overview of topics, there are SOME MANY subjects missing here that you'll be finding in your study path (Roles, EJB 2.x Interoperability, Restrictions, Requirements, etc etc etc.). This is just to help you start.
Regards,