Trusted as stable file and print server software, Samba is now creating
a groundswell, triggered by the long-awaited release of the latest
version, Samba 3.0.0. There are currently 14-16 million servers running
Samba, with an expected 3 million soon to migrate. If you're a longtime
Samba geek or a Windows network admin thinking about making the switch,
read this interview with Samba Team co-founder John Terpstra.
Its a good article and also has links to the reference guide and howtos.
If you are thinking or using samba, I suggest it as a good background.