This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
have a look in the links section. I personally used Cade and Roberts (Sun Certified Enterprise Architect for J2EE technology), Fowler (UML Distilled (3rd ed)), Alur, Crupi, and Malks (Core J2ee patterns), and the GOF books for Part I and found it quite easy.