Start with your network design. You need to look at a separate subnet for your DMZ segregated from everything else by a firewall. Ideally all servers in here will be members of workgroups and not members of your domain to reduce the amount of ports you need to open on the firewall as each one you do reduces the security the DMZ is designed to give you. Installing windows - standard install really but look to set all unnecessary services to disabled to reduce the attack surface of the operating system. For everything else have a search around the web for info. www.phoneboy.com used to be a good source of information of securing the o/s but i have not looked at it in a while. hth and good luck,