For the part 1 exam I read:
Sun Certified Enterprise Architect for
Java EE Study Guide (2nd Edition)
http://www.amazon.com/Certified-Enterprise-Architect-Study-Edition/dp/0131482033
EJB 3 in action by (excellent book)
Core J2EE
Patterns
Core JavaServer Faces (3rd Edition)
http://docs.oracle.com/javaee/5/tutorial/doc/
I mainly worked by Mark Cade's book. Identified the areas I'm lousy at and read more books about them.
For part2:
Got the DreamCar assignment.I followed the example in Cade's book.
Except for the deployment diagram. Many people failed because of this.
Try googling about deployment diagram. There are lot of posts on this forum that are helpful for Part2.
I wrote in detail the hardware specification.Clusters for performance, physical nodes for availability, DMZ for security etc.
http://www.agilemodeling.com/artifacts/deploymentDiagram.htm
http://docs.oracle.com/cd/E17904_01/web.1111/e13709/planning.htm
Constantly add/edited assumptions while doing the diagrams.
Read UML Distilled by Martin Fowler
Used StarUML(needs some time to get used to)
Part3
The essay part consist of 8 questions in which you have to defend your design.
I personally think I could have done this better. You have 2 hours to answer the questions. It wasn't enough to explain everything properly.
Good luck