Upgrade of a SBS2k Network.

I can not locate a project guide on Upgrading of a SBS2k Network to Win2k AS w/Exchange. I need a little direction. MS told me there was no way to upgrade, that we would just have to do a clean install. I am willing to do that, but if I can avoid itgreat if not, are there any project guides for installing AS w/Exchange Server 2k? Thanks for the Help.