I've managed to configure a Samba Server as a MicroSoft Windows Primary Domian Controller.The [global], [homes] and [share] sections seems to be doing what they should be doing.
LDAP and PAM support is excluded for now, but hopefully some time in the near future, i'll be able to hack on it.
I also suggest the book "Using Samba" which has been officially adopted by the Samba Team and is under the GNU Free Documentation License.
I'll also upload a Sample Samba Primary Domain Controller Configuration file on my hacks page. Hope it helps.