Go through the api docs properly.You can visit it here.
Then SCJP6 study guide By Kathy Sierra and Bert Bates is a wonderful book to get prepared for SCJP. After doing this to test your knowledge on the subject, give the mocks like masterexam which comes along with book's cd and Examlab which is a free simulator. This is enough to prepare you thoroughly for the exam.
[ SCJP 6.0 - 90% ] , JSP, Servlets and Learning EJB.
Try out the programs using a TextEditor. Textpad - Java 6 api