Any link to Portlet sample for a Newbie Portlet developer

Hi
Since I am newbie developing portlet I would like to hear if any have suggestion to Portlet sample that have a Input form that is validate when it is submittes.

Generally any sample that can give inspiration to build a porlet that show a list, an a user can add to the list creating some input..

I will be happy if it could be a portlet sample created in Websphere portal server.

I am really Stuck an can not continue.
Thanks in advance.