If you are still puzzled about how to creat a sharepoint webpart,these following articles can help you out.
- Create SharePoint Webparts With ASP.NET User Controls (+ Demo Video!)
- User Control Container Web Part
- User Control & WebPart : a new way
And at Kaneboy's CodingLife Blog,he gave us a very comprehensive demonstration of its development and deployment for Microsoft SharePoint Webpart.Nice job,Kaneboy.