Try looking at either the SPListEventReceiver class or the
SPItemEventReceiver class.

SPListEventReceiver: http://msdn.microsoft.com/en-" target="_blank" rel="nofollow">http://msdn.microsoft.com/en-
us/library/microsoft.sharepoint.splisteventreceiver.aspx

SPItemEventReceiver: http://msdn.microsoft.com/en-" target="_blank" rel="nofollow">http://msdn.microsoft.com/en-
us/library/microsoft.sharepoint.spitemeventreceiver.aspx

yes Event handler is a good option for you.

I agree event  handler is a good options. What I
am interested in is what type  of project  do you create  to contain a
"SharePoint feature"? Is there some special *.xml file that has to be
created to support a feature? If so does someone have a sample project that
they can share that contains a SharePoint feature?