Domain Authentication

[Martin]

I've been poking through docs and non-searchable mailing lists, but I 
haven't found the answer to this yet. First of all, how do I verify that 
my domain registration is accurate? My system seems to be in the NT4 
domain, how do I prove it?

Second, how do I specify users and groups in a domain as valid users for 
a resource? Do users still log in as DOMAIN\username? And how do I add 
users and/or groups with spaces in them to the list of valid users for 
accessing a resource?

Thanks.