Check out
the Bunkhouse. I'm a real fan of
SCWCD Exam Study Kit -- Manning Publisher.
As for how long it will take you to study -- it all depends on how much time you can dedicate to it, and how quickly you pick up on the subjects. It took a friend of mine a week, but he was very well versed in JSPs/Servlets already. Other people it might take a a few hours a night for a month or two.