During number of training I often got questions on the installations of MOSS where people were using WSS 3.0 instead of MOSS after running the MOSS Setup. I was installing MOSS on a demo server so I though why not to take snapshot and make a step by step document.
The document is available
Installing SharePoint Server 2007
del.icio.us Tags: MOSS 2007 Installation, SharePoitn Server 2007 Installation a nd Configuration
Jerry Yasir's Blog 
Great tutorial. Also see my two-parts video on how to Install MOSS 2007 step by step:
http://www.rodneyviana.com/portal/Sharepoint/MOSS2007Install1of2/tabid/55/Default.aspx http://www.rodneyviana.com/portal/Sharepoint/MOSS2007Install2of2/tabid/57/Default.aspx