Hi,
the Khalid book you hold can be pretty comprehensive. For example, the last Chapter 11--The Collections Framework, at least 80% in that chapter is not required for the exam. However, you'll understand things better if you know a little bit more. That's the Khalid/Rasmussen approach I like.
The java.lang package and all its methods for the
Java API was my weak spot for the exam(and I did pretty OK the rest). Because prior to taking the exam I did not had Java work-experience with this package. It seemed stupid to learn all the method signatures. I think a programmer should refer to API when he feels a particular class service is needed.
I'd suggest learning the most important methods in the Wrapper,String(buffer),Object class. Try to group the methods by their behaviour, you'll remember them more easily.
Hope this helps,
Ice