There is a section in the ActivePerl docs entitled "Using PPM", which looks quite helpful. Read the docs (which can be found at http://aspn.activestate.com/ASPN/docs/ActivePerl/5.8/faq/ActivePerl-faq2.html), play around with the GUI, and let us know if you still have questions. I found the GUI fairly easy to use. Good luck.

Update: please also read "Question" vs "Doubt"