To be honest, I thought the test was much simpler than my score suggests.
Preparation: 1. Head First Servlets and JSP; an absolute must-read. The Coffee Cram is really hard; I postponed taking it until the day before the test, which was probably a bad thing. 2. The Manning book - Deshmukh and Malaviya. Very good for quick reference. Crisp and to the point. 3. Mikalai Zaikin's and Marcus Green's notes.
Tests: 1. Enthuware - recommended 2. Marcus Green 3. JavaBeat. I found this set of questions very easy to solve.