Lanman,
You need to read the security guide for Windows Server 2008 R2 SP1. Below Microsoft Baselines you see the list of products, below each product there's a folder called Attachments/Guides, it contains the security guide and other resources for that product.
Since you're new to this stuff I suggest that you read the entire thing, and that you pay particularly close attention to chapters 2, 3, and 4 as they contain the key information you're looking for.
Kurt Dillard http://www.kurtdillard.com