Hi slim_
Sorry 'bout that!
Lets go to the first site I get when I put "samba add user" into Google -
http://www.samba.netfirms.com/addusers.htm - although it's at the command line they do step you through it with illustrations.
The index page for that site -
http://www.samba.netfirms.com/index.htm - has a very easy and lucid guide to SMB networking between Linux and Windows generally.
Allbest
Mac