The best walk-through I have found on the web is here: Installing Microsoft Office Sharepoint 2007 (MOSS 2007)
If you are following this, make sure that after you install the Shared Services Provider that you remove the ipv6 entry from the host file that the wizard creates, other wise all the web sites in Sharepoint will return a Service Unavailable error message.
There is specific option you select that will avoid you doing this as described here: IIS7: Sharepoint 2007 fails with 503 Service unavailable errors
Hope this helps.
dmportella
