1) go to sun site and try to do as much as possible on the java tutorial..
2)get certification book by roberts and read line by line the relevant chapters(must,must)..
3)start with mock exams and complete all the exams from www.javaranch.com/maha
4)try to do the exams till you get 85% consistently(particularly marcus green mock exam)
5)go for the final test..
hope this helps