Here are some links which will give a quick introduction http://blogs.msdn.com/jerem... http://blogs.msdn.com/jerem... http://blogs.msdn.com/jerem... http://blogs.msdn.com/jerem... ......
A Crash Course on ASP.NET Control Development: Design-Time Features and Capabilitieshttp://msdn.mic... an .ascx User Control into a Redistributable Custom Controlhttp://msdn.microsof... ......