Debugging your application attached to remote IIS.

http://www.codeproject.com/KB/aspnet/IISRemoteDebugging.aspx

http://msdn.microsoft.com/en-us/library/bt727f1t.aspx

Debugging your application attached to IIS

http://www.codeproject.com/KB/aspnet/ProcessAttache.aspx

Debugging in VS 2010 - Basics

Below is the which gives complete overlook of debugging option in VS 2010

http://www.codeproject.com/KB/cs/MasteringInDebugging.aspx

http://weblogs.asp.net/scottgu/archive/2010/08/18/debugging-tips-with-visual-studio-2010.aspx

http://www.codeproject.com/KB/debug/VS2010Debugging.aspx