Howtogeek posted a tutorial about setting up DHCP in Windows Server 2008 R2

This guide assumes that you have Server 2008 up and running on a machine–if you don’t, you should check out our guide on how to install it. You should also have set a static IP address on the server before continuing.

To get started, fire up the Server Manager, right click on roles, and then select add roles.

  How to Set Up DHCP in Windows Server 2008 R2