Hi Sudha,
You should definitely try for the SCBCD exam. The latest one is the 5.0 version. And there is absolutely no use of searching for a HeadFirst book of the 5.0 version of the exam because of a simple reason - The book does not exist.
However, you can prepare for the exam from many other resources. Ill tell you what i am doing/have done.
I read the "EJB 3 In Action" which is quite a good book to get started.However i faced a lot of problems to actually get my code running because i was completely new to the EJB area of J2EE.So, i tried to read "Beginning EJB 3 Application Development" to learn to execute my code on the Glassfish application server.I did most of my coding by hand and occasionally used the Netbeans IDE.I am also referring to the EJB 3 JPA book which i can definitely say as one of the best(technical) books that i have ever come across. It is a must read not only for the exam but also to actually enjoy the concepts involved in the JPA technology which is also a part of the exam.You can find Mikalai Zaikin's SCBCD 5.0 Guide here which i see has been recommended by many. I havent started it yet, but i think i will have to go through it after all the appreciation that it has received.Then comes the EJB 3 specification and the JPA specification which i am currently going through. And i must say that it is extremely good if you are seriously interested in passing the exam.
Its a huge list,but, Sun Certifications are more like a journey. And this is one journey that is as enjoyable as the destination. If you really love the technology, you will definitely love each and every moment you put into your preparation. The knowledge you can gain is really worth all the effort. So, just dont bother if you have any experience or not. I dont have any experience either. Just go ahead and give it a shot. Anyways, you will end up with more knowledge than what you have today.
So, Good luck!
Regards,
Ryan Sukale