Asim,
Great question... The PrepCast is a great start to your PMP studies and it's how I earned the PDUs needed in order to meet PMI's requirements for certification. However, I don't think many of us would say that's the end of the studying. I strongly recommend another study source (such as Rita's book) before delving into the practice tests. Some people read the entire PMBOK cover-to-cover one or more times as well (I did not do this, but I used the PMBOK as a reference and a way to resolve questions I had).
You can also check out the Lessons Learned forum (
www.project-management-prepcast.com/kune...exam-lessons-learned
) to see how others approached their studies. You can adapt others' experiences to your own needs and style.
Best of luck!
Tracy