Hey Rashmi,
I suppose that all depends on how well you know
Java to begin with. Since JQ+ comes with 9 mock exams, one approach you might want to take if you don't want to go through an entire book is to take the first mock exam as a diagnostic
test, to determine where your weak areas are, and then study up on those. I don't think it's a great idea to use too many of the JQ+ questions until you are approaching exam-time. The questions really are spectacular indicators of your preparation, and I found that they were not as beneficial a second time around since I managed to remember most of the original answers. I'd say save most JQ+ and Marcus Green's mock exams (
http://www.jchq.net) until you are close to taking the test and for earlier in the process use other mock exams listed on this site (go to Gramps, then Java Certification, then "A List of Java Certification Mock Exams") as well as the "Rules Round-up" game here at Javaranch.
Hope that helps, Good luck on your test!
Matt
