I did not use the K&B book for my certification, but I have heard excellent things about it. If you're looking for a good book, I would recommend checking out the Bunkhouse here on JavaRanch. We have a vast array of book reviews - that link will take you directly to the certification section. Like I said, I've heard great things about the K&B book, but I used Mughal and Rasmussen and found it very good. As far as Dan Chisholm's mock exams go, Dan is currently having some problems with his hosting company. His exams can be found at an alternate location for the time being - you can read all about it here. For more great links like this, be sure to check out the SCJP FAQ at the top of this forum.
The best thing about the K&B book is that they have "two-minute drill" bullet points at the end of each chapter. You can print those out and have a comprehensive and concise list of almost everything you need to know for the exam.