Sure. I rerfered only 2 books. First book was "Java 2 The complete reference" by Naughton & Schildt and Another was "Programmer's guide for
Java Certification" by Khalid Mughal. Read the Khalid Mughal book atleast 3 times. Its a really good book for exam purpose. After that take as many mock exams as you can. These exams really help you develope the concepts. I took more than 2000 Que from mock exams. Particularly JQ+ exam is really good.
Don't forget to visit the Javaranch discussion forum daily. it will help a lot.
Rakesh