You should look at the SCJP FAQ and you will find answers to all your questions there. It contains a list of books and mock exams for preparation.
Usually everyone starts with SCJP Study Guide by Kathy Sierra and Bert Bates. After completing the book, just go through mock exams. They will give you good idea of how the real exam will be. The book comes with a CD which has 2 exams and one bonus exam can be downloaded from the companion site. You can give free mock exams or can go for paid mock exams. You will find all the details in the link that I gave. If you have any doubt just ask it here and you will get a good explanation by the Gurus here.