Jack, VNC is a good program but if you're running a Windows 7 Pro or Windows XP Pro computer Terminal Services (RDP remote desktop protocol) is already built in and ready to go. You just need to turn it on and configure your router. It's actually pretty simple and works really well.
http://www.howtogeek.com/howto/windows-vista/turn-on-remote-desktop-in-windows-vista/
http://www.howtogeek.com/howto/windows-vista/turn-on-remote-desktop-in-windows-vista/

