[Samba] Ubuntu as Samba Domain Member

[John Aviles]

Hi All,
I need your help with my problem. I want SAMBA to be the PDC for my Ubuntun workstations. The SAMBA in installed in Ubuntu also the version for the server and workstations are 12.04. I have successfully joined the workstations to the SAMBA server but I can't login to it using the users I created in SAMBA. Can you anybody tell me the steps on how to do this? Do I also need to add the Ubuntu workstations in SAMBA?
Regards,
John