I recently changed careers from a non-IT background. My company requires a SCJP cert and gives limited time to achieve it. I hope this post will be an encouragement to others who may be in a similar scenario.
I used two main books and will comment about both:
SCJP 6 by Bert Bates and Kathy Sierra - This IS the book to pass the exam. That being said, at first I found it extremely challenging. I often had to read a chapter several times. I failed the quizzes miserably the first time through. The authors intentionally use the quizzes and mock tests to make sure you understand the concepts, which is good even if it can be a blow to your pride! The key is to stay with it. Learn one concept at a time. If you get an answer wrong, see it as a learning opportunity. Although it seems like a lot, there is only a finite amount of material the exam can ask you and each question helps you come closer to mastering it.
After spending over a month studying the K&B book I was running out of fresh questions and still wasn't sure if I was ready for the BIG test. I decided to buy the Sun Certified Programmer for Java Platform Study Guide by Richard F. Raposa I basically used it for the chapter quizzes and two mock exams. The questions were a good confidence booster and helped round out my understanding. I hear K&B are coming out with a second book of just sample questions this fall and would imagine it would be a huge plus as well.
Comments about other sites: There are a lot of good websites out there, but I found MANY of their questions to be out of the scope of the exam. I would only use a limited amount of time and focus on the two books I mentioned.
I was scoring 80% on the K&B and Raposa mock tests and quizzes and passed the real exam with a 76%.
Tips for studying: Write code samples if you don't understand something. Don't neglect the basics ~ that's were I lost most of my points! Review, review, review.
Tips for the test: Don't panic. Take it one question at a time. Use process of elimination. (I had a coworker tell me he almost left in the middle of the test from frustration and scored an 81% in the end!)
And remember, if the exam was easy, it wouldn't be valuable. Best of luck!