Now that we have the Commerce Server SP2 the following documentation has also been updated.
The documentation was updated to include Windows 2003, 2008, XP and Vista as well as the .NET Framework 3.0 and 3.5 with Visual Studio 2008.
You can download you copy at Download details: Commerce Server 2007 Install and Readme documentation, happy readings.
I would highly recommend that you spend a few hours and read these documents (the Install Guide has even pictures :)).