Adding domain groups?

[goku21]

Alright, I've tried a search and no luck. I'm hoping someone on the forums might know how I can add Domain Groups to the Adminstrator group. The only steps that I know that I must take so far is that I have to join my computer to the Domain first and then login to the domain, but there in lies the problem. After I join the domain, will I log into the domain on my first auto login or will it log me into the workstation only? Also, I can't figure out for the life of me how to add a domain group either!