Well my friend, the secret to SCJP is hours of hard studying and code
testing. If you dedicate time and effort to it then you can do it in July.
Best book is Kathy Sierra and Bert Bates
Sun Certified Programmer for Java 6 Study Guide. For mock questions you need to do as many as you can.
ExamLab is one good software and it is free.
If you have any questions or topics that you are not clear about, you can post the question and the code here and we can try to help you understand it, just make sure to cite the source of the question and where you got it from.
Good luck for the preparation.
Cheers!!