The best book hands down is: The Sun Certified Java Developer Exam with J2SE 1.4 by Mehran Habibi ISBN: 1590590309 And an extra bonus, Mehran (max) Habibi monitors this very forum. He gives some excellent answers. How long does it take? According to another book I read sun estimates between 100 and 120 man hours of programming. And this does not take into account design, testing, and getting familiar with the language. It seems that most take around 3 months for all of this.
The timeframe is pretty dependent on your amount of Swing knowledge. I had had quite a bit of Swing experience prior to the exam, so I didn't have to take the time to learn how everything works. If you haven't worked with Swing before, you might want to take a little time to get familiar with it, especially working with JTable. The LayoutManagers can be tricky in the beginning and you'll save some frustration with the exam if you get some base knowledge of them before starting. Good luck!