One of the things you'll notice quickly is that by default, Windows Vista will not map samba shares - nor can you use Samba as a PDC (Primary Domain Controller). This is due to the default security policy of Windows Vista only using NTLMv2 for authentication - something Samba doesn't support as yet.
To fix this, run (Win+R) "secpol.msc"
Navicate to Local Policies -> Security Options
Change the value of the policy "Network Security: LAN Manager authentication level" from "NTVLM2 responses only" to "LM and NTLM - use NTLMv2 session security if negotiated"
This should now allow Windows Vista to both map network drives based on Samba servers, and use Samba as a PDC.