I did about two weeks intensive preparation using "Head First Servlets and Jsp". Got 74% in HFS mock exam - consistent with 72% and 91% for HF EJB mock exam and EJB real exam.
Used Javaranch a lot too. Any doubts and I would first head for the search page on JavaRanch. I almost always found an answer there.
Thanks Bryan, Kathy, Bert and everyone at JavaRanch