Although I haven't post anything yet, I have been around for quite a while. Needless to say, Javaranch is a good site. Like many people have said it over and over again.
I studied SCWCD and SCBCD for about 5 months and got good scores with them. Initially I only want to pass because I know those ceritificates are not as useful as real experience.
Here is my detailed experience:
SCWCD: about 3 months and scored 89%. I had plenty of experience already but still don't know a lots of thing.
1. used Hand First
Servlet and
JSP mainly (read more than 4 times)
2.
www.j2eecertificate.com (more than 2 times)
3.
www.jdiscuss.com (more than 2 times)
4. Mikalai Zaikin' note (one time, it is good, still)
SCBCD: about 2 months and scored 91%. I only have learning experience before. SCBCD is easier than SCWCD.
1. used Hand First
EJB 2.
www.ejbcertificate.com 3.
www.jdiscuss.com 4. Mikalai Zaikin' note
I almost didn't use any other materials except above. These are far more enough if you really study these materials carefull.
I genarally only spent one or two hours a day, but almost every day.
Also I skipped those questions/materials which I think they are hard to understand. You don't need those if all you want is to pass and get a good score. Of course you may need them if you really want to learn.
One important thing for those who worry if they can pass. I should say everyone should pass if you really want to and spend your time to it. I also wonder how difficult those certificates are. Now I have gained a lot of confidence by taking them. This maybe even more important than exams themselves.