The Samba home page, at http://samba.anu.edu.au/samba/, is the definitive source for news and information about Samba. The documentation distributed with Samba is relatively unorganized, but covers every aspect of server configuration. If you have questions about Samba, first consult the FAQ, then try the Samba Mailing List. The location of both can be found on the Samba home page.
The book Samba: Integrating UNIX and Windows, by John Blair and published by SSC, covers all aspects of installation, configuration and maintenance of a Samba server.