1 Core J2EE Patterns: Best Practices and Design Strategies, Second Edition
2 Head First Design Patterns (Head First) [Illustrated]
3 Sun Certified Enterprise Architect for J2EE Technology Study Guide
4 UML Distilled: A Brief Guide to the Standard Object Modeling Language, Third Edition
The SCEA exam is combined with three parts, Step 1(CX-310-051), Step 2 (CX-310-300A), Step 3 (CX-310-061). 051 is a choice
testing. You can read through book3 to prepare this part, and also
you should be familiar with knowledge on patterns(book2, or GOF) and UML(book4). 300A is an assignment exam. It examines your ability to apply the general architecture and j2ee kowledge to a business scenario and provide a J2EE solution. Book1 would tell you how to design a robust J2EE system. For 061, don't worry about it if you have finished step2.