i prefer epractize labs preparation kit
http://www.epractizelabs.com/scjp-exam-5-prepkit.html i really apreciate the preparation components of this product(plan - setting the goals against the topics and schedule),practize(review tips, worked out programs,mock exams) and achieve(traking based on goals/schedule set).
my preparation guidelines
1. understand the exam objectives (the theory part)
2. prepare more program examples
3. workout with set of mock exams
4. continue your progress till you get confidence to take the real exam
~ sherly