Yesterday, I passed the SCJP 1.4 exam with a score of 78% (although I should have scored higher!) I've been browsing JavaRanch in the last month and I have to admit that this site has the best resources for preparation.
My primary source was K&B - the only book you need to pass (as indicated on this forum). As for mocks, I used the JQPlus v4 enthuware mock simulator since its free (Thanks Enthuware!), as well as a few free online mocks I could find.
I would also like to add that the Review questions at the end of each chapter in K&B really does prepare you for the types of questions for the 1.4 exam (difficulty is about the same). Instead of just simply reading the 2-minute drills, do the review questions in place of this. I find that you could be quite passive just reading, doing the questions will help you identify your weak areas. Scoring 80% or higher is a good way to know if you're prepared to write the exam. Overall the exam was NOT as difficult as I thought it would be, but at the same time it is NOT a walk in the park either.
Thanks to Bert and Kathy for such a great and easy to read book !