How to secure a windows 2008 server
As long as you keep on top of the security updates and have a paranoid approach to your firewall you will be fine.
- Lock down connections to specific IP's if possible
- Only open what you need and firewall them off to specific applications or services.
- Have ultra-secure passwords.
If you really feel like being paranoid move RDP away from 3389 and move it to another port.
The best way? After you've got things installed, configured, and running, run the Security Configuration Wizard.