After you deploy the SUS server, you need to make sure all of your clients have at least Windows 2000 service pack 3, which is required for the automatic update client to point to a corporate SUS server. Also, eash of the clients needs to be configured to point to your corporate SUS server. The easiest way to do this is through Active Directory group policy, though the settings can be applied manually. For more information, see Microsoft's SUS Deployment White Paper, available here:
http://www.microsoft.com/windowsserv...eployment.mspx

While SUS does a good job of determining what patches particular clients may need, it is not very controllable in how it reboots your client workstations. My recommendation is a system like SMS for the majority of the patch installations, with SUS being used to cover any clients missed by SMS.