Hi fellow JavaRanchers,
With 5 hours of everyday effort in weekdays and 12 hours in weekends, it took me 1 month to complete it.Follow the instructions in the book (Re-read the Two-minute drills and exam watch notes, re-take self tests, try out exercises and lastly write lots and lots of code (My favorite one)(Tweak the given code and find out how the output changes)). It took me two more weeks to re-read exam watch notes and two-minute drills, re-take self tests and take mock tests (Master Exams A and B in the CD that comes with the K & B book are the only ones I took) and quizzes (Rules Round-up games in JavaRanch).
I scored 91% in OCPJP 6 yesterday. The exam had 60 questions that must be answered in 150 minutes.
The questions were shorter and trickier when compared to mock tests and Master exams (that comes in CD with SCJP 6 Study Guide by K & B). There were fewer questions from threads and generics than I expected (about 5 in each). I was able to complete the exam in 2 hours.
Here are some preparation tips that could help you:
1. If you are currently working in Java, SCJP 6 Study Guide by K & B is all you need.
2. If you have been out-of-touch with Java for a while, or if you are new to it, Head First Java by K & B would be of great help. With 5 hours of everyday effort in weekdays and 12 hours in weekends it would take about 2 months to complete the book (That includes the time you need for trying out the project in the book). Then, you can start with SCJP 6 Study Guide by K & B.
All the best!
Finally, thanks to K & B for the wonderful books. Your language and humor at unexpected places in your books (SCJP Study Guide as well as HFJ) kept me going at tough times. JavaRanch for the answers to queries, tips, FAQs and Rules Round-up games.