Joining a 2008 member server to a 2003 domain?

I need some help to join a Server 2008 member to 2003. I am not getting the right steps to do this. I tried to use Group Policy for that, but it looks ab it complicated. Has anyone done this before. If yes then what are the options available. How can I assign a set of privileges to that members on different domain. Thanks.

You can start with DC domain. You can make the member to join the DC first. There is no custom gpo available that can offer you option to configure the permissions and other controls. But I found a link below which has some relative information. There are different kind of process provided for different methods you want.

Adding a Server Running Windows Server 2008 to a Windows Small Business Server 2003 Network