Sorry, that is a massive area. You need to read and download Business Desktop Deployment:
http://www.microsoft.com/technet/desktopdeployment/bdd/2007/default.mspx?WT.mc_id=bddov
From the tools/add-ons that you can get with BDD 2007 you'll need imagex and WinPE 2.0.
It's really too big for someone to give you a step-by-step here, you should probably just give it a go and report problems which we can help with.