The Sysprep How-To
http://community.spiceworks.com/how_to/show/1752
Sysprep is a great tool to use that comes with your Windows clients on the CD. This how-to will focus on Windows XP version of sysprep, however at the end you will find multiple resources and how-tos for ImageX and Sysprep for Windows 7.
See article at Spiceworks