The most common tip I got from fellow ranchers was to read the assignment over and over for days (or even weeks) before starting with your design.
If you're gearing towards a JEE 1.4 solution, then
Core J2EE Patterns is a must have. However, if you're planning to submit a JEE 5 Solution, then it might be worth buying any of the EJB3 books below.
Enterprise JavaBeans 3.0 (5th Edition) Mastering Enterprise JavaBeans 3.0 Pro EJB 3: Java Persistence API (Pro)
Also make sure to get a UML book since a significant part of your assignment score for the old
SCEA will depend on UML compliance. Below are some of the top rated UML 2.0 books.
UML 2.0 in a Nutshell UML Distilled (3rd Edition) [ December 01, 2007: Message edited by: Paul Michael Laborte ]