First of all I am really thankful to all the members of forum who provided quick and precise answers and gave guidance towards understanding java in a simple way. I am also thankful to Kathy and Bert for compiling this awesome book called SCJP. It has one of the best yet simple way of teaching along with some really difficult practice questions that tests your knowledge at every step.
It was very beneficial for me to read the experiences of members who had passed the test previously and as gratitude I'd share my experience hoping that it'd help future candidates in their preparation.
How it started ?? I started as a complete noob in java 3 months ago. Though i knew C but seeing that that scary stuff in java program with it's loooooong class names was very frightening. After i decided to study java i realized that it's very simple as compared to C. I studied basic concepts for about 2 months ans then started preparing from K&B book a month ago.
Approach I will strongly suggest buying a hardcopy of K&B book(I heard this one is also good). Having a hardcopy will help you in taking the approach that i used.
Step 1 Read the book. Highlight all points that you think are important.(Highlight even if you already know it )
Keep doing the exercises mentioned and the practice questions at the end of each chapter.
Step 2 Once you've finished the book and all exercises it's time time further refine the criteria that needs memorization.
In second step try to add all important points in a single A4 size sheet(write both sides). Some chapters may take 2 pages (like chapter 6 & 7 for me) but that's ok.
As you have already finished the book in step 1 your knowledge level has also increased. So from now on while revising you'll only have to read these 10-12 pages that hold the most important rules alone with some marked pages.
I suggest using sticky notes like this as bookmarks. Write what you're bookmarking on top (eg- rules of overriding page) and it'll be very easy to check it whenever needed.
Step 3 Start doing practice tests about 15-25 days before the exam. Your aim should be to give a minimum of 1 full practice test every 2 days. I suggest taking a minimum of 4-5 such practice tests.
Thoroughly review your performance in every exam. This is the most important step. Make a new A4 sheet bundle and write the new things/rules that you learned while reviewing the practice exams. I was able to make a list of about 100 points that weren't explicitly covered in K&B book but were still there to learn.
Step 1.5 - 3.5 This is a continuous process of making logs to review your performance. Make a log in MS Exel or wherever you like. If you manage to get 61% and above in the self test questions given at the end of book mark that chapter as Green else mark the chapter Red. Red means you'll have to re-read the chapter as your concepts are still weak.
Similarly make a log for the practice exams also that you took. Here's an example of how i tracked my progress. The fields in Red needs attention.
I got 25% in the Examlab diagnostic test and believe me i learned the most from reviewing this test.
Some points : 1: Although you can get appointment for exam 2-3 days prior to the intended date but just to be safe schedule it atleast 1 week in advance. I had to postpone my exam by a week as all the slots were taken by some other university for their domestic examination. This could be frustrating if you are on a time frame like i was.
2: Code. I didn't do lots of code but you have to be sure whenever you are in doubt. And the best way to clear the doubts is to ask java itself. The members here are also very helpful in clearing doubts.
3: Don't be discouraged if you score low. Take every practice exam as a opportunity to learn(I scored 25% in my first exam). Give the exams seriously.
4: Revision before the exam is most important. Revise the notes you've made before the exam.
5: Getting a score of 50-55% on most exams is a good indication towards passing the real one. The OCPJP exam is a lot easier than the practice exams.
6: There is no shame in postponing the date if your preparation is lagging. Remember that the most important thing is to Keep Moving Forward