The best study material you can get on internet. It may be too bulky to go through all of it but if you have time in hand before exams you should definitely study these tutorials. It will help you clarify the fundamentals of java programming.
Another free tutorial specially design for SCJP preparation and self evaluation purposes is available on following Link.
This tutorial consits of 10 section in downloadable pdf format.
Another nice tutorial for SCJP preparation.