There are multiple ways to remote control computers and servers on the documation.com network. The method you use will depend mostly on the computer you need to connect to, and to a lesser degree what you need to accomplish on that computer.
If Remote Desktop is not enabled on the remote Windows computer you can enable it:
Mac computers using OS X refer to remote control as “Screen Sharing.” Screen sharing with Mac has a client component and a server component.
To remotley control a Mac computer you must enable the server component of screen sharing.
If you wan to connect to another computer from you Mac you need to use a client application. OS X comes with a program for this purpose. The program is aptly names 'Screen Sharing'. It can be found on the hard drive in the following path /System/Library/CoreServices/ScreenSharing. You can create an alias to you desktop or Allications folder, or you can launch it and lock it to the dock. Alternatively there is a third party client available from TightVNC at http://www.tightvnc.com/