.NET Data Access Architecture Guide :Drag-and-Drop Operations

Performing Drag-and-Drop Operations in Windows Forms
Drag-and-Drop Operations and Clipboard Support
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vbcon/html/vbcondragdropclipboardsupport.asp

Architecture Guide is available at
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnbda/html/daag.asp