I have also gone through (if not every page, at least some important chapters) of Head First Servlets and JSP book by Kathy Sierra, Bert Bates and Bryan Basham. That is a good book and did discuss certain things that David Bridgewater didn't.
As usual javaranch.com is a good website to get links to mock exams, notes and other details related to certification exam. If you can prepare some notes on your own, keep life cycle diagrams and APIs handy for quick reference.
I have taken good number of mock exams in various websites. But there is some confusion. Some mock exams are outdated. They still talk about questions which are not relevant to SCWCD 1.4 anymore. However, taking mock exams is always important.
Questions from Enthuware exams are good. But SCWCD 1.4 means remembering a lot of API and what is allowed and what is not. Some times, order of things and so on. More work with memory than logic.