samba - Feb 2004 - Authenticating a Red Hat Linux 9 machine to a Windows 2003 native AD Domain

The article at http://windows.ittoolbox.com/documents/document.asp?i=1893
 
is a little dated.
 
Digital signing is also required in my AD, something this article said was
not available at time of writing (06/13/03) but would be incorporated into
the final release of Samba v3.
 
My machine is a mail server, so the file/print sharing will not be used
initially.  Would just like to have a way to authenticate this Linux
machines into a Windows 2003 native AD.  
 
Pointers to documentation and/or steps would be helpful, as I am sure this
question has been asked and answered many times before.
 
Regards,
 
Edward W. Ray