Believe me best book is SCJP book by Kathy Sierra and Master exam.
I basically did four things
a. Read Kathy Sierra book 2-3 times end to end to understand each and every concepts
b. Master Exams and did each question present in Khalid Mughal SCJP 6 book
c. Followed all JavaRanch post since last 5 months
d. Did topic wise questions from this link
I did not attempted Examlabs as i use to read on JavaRanch that examlab questions are tougher than actual SCJP exam questions. Sorry Deveka.....
Today i revised all Two minutes drills (present at the end of each chapter) and some prep notes that i had prepared while studying from Kathy Sierra
Also I use to read testimonials posts of all peoples who have cleared SCJP and got more and more motivation to clear SCJP.
In all, thanks to Kathy Sierra for writing excellent book.
Now i move to SCWCD forum
Time to change my signature from "Hunting SCJP in Java forest created by Sun" to "Hunting SCWCD in Java forest created by Sun"
Oracle certified Java 8 Programmer I, Oracle Java Web Service Developer (1z0-897), Oracle certified Java 7 Programmer, SCJA 1.0, SCJP 5.0, SCWCD 5.0, Oracle SQL Fundamentals I, CIW Certified Ecommerce specialist