how to add a Server2008R2 server to a SBS2011 network?

Hi

I am about to soon be setting up a new SBS2011 server on a new network.

They want their old server to be used to offload some of the workload so we are putting Server2008R2 on it, so the SBS CALS cover the second server.

How do I join the second Server2008R2 to the SBS2011 Server?

Does that replicate AD information for log ons and file/folder control?

I want to try this out in a virtual environment first as a dummy run so I know exactly how to get it working when I do the install.

Thanks

Tris