How should I prepare to use TS Licensing?
To use TS Licensing to manage TS CALs, you will need to do the following on a server running Windows Server 2008:

1. Install the TS Licensing role service.
2. Open TS Licensing Manager and connect to the Terminal Services license server.
3. Activate the license server.
4. Install required TS CALs on the license server.

For a detailed instruction, browse to: http://technet.microsoft.com/en-gb/library/cc754034(WS.10).aspx

Keep in mind that a terminal server running Windows Server 2008 cannot communicate with a license server running Windows Server 2003. However, it is possible for a terminal server running Windows Server 2003 to communicate with a license server running Windows Server 2008.