Hi Friends,
Thank you all for your help and guidance, I finally passed the exam after 56 days of preparation

.
I studied Head First
Servlets and
JSP book almost twice and then learned about new features in Servlet 3.0 from some blogs etc., practiced a lot, then read some selected chapters from Servlet 3.0 specifications, and took Enthuware mock exams.
My suggestions for others who are preparing for the exam:
1.
Write a lot of code. I didn't use any
IDE, just notepad and
Tomcat 7. For exam you have to remember a lot of things like tag syntax, EL, DD elements, tlds, tag-files, annotations etc. Writing a lot of code and making it work will help you remember things easily and build up you confidence about what you've learned.
2.
Don't ignore new features in Servlet 3.0: Exam had plenty of questions about them. Broadly, they can be categorized in three types: 1-Annotations, 2-Web-fragments, 3-Asynchronous Support. From Servlet 3.0 specification must read chapters are: section 2.3.3.3: Asynchronous Processing, chapter 8: Annotations and Pluggability, Section 13.4.1 @ServletSecurity annotation. Read blogs about new features and most importantly Code,Code,Code...
3. Buy mock exams:
Enthuware mock exams are really very good. They reflect the difficulty level of real exam. In the last mock exam I got 89% which is very close to my actual score 91%.
4. Actual exam is
difficult so take it only when you are confident enough about your preparation.
Once again thanks a lot and good luck for preparation.
Next: I am planning to learn Hibernate and Spring.