How to Use Your Mac as a Server:
Turn your Mac Mini into a server! Yes, that's right, with a little know-how and a little spunk, you can turn an inexpensive Mac Mini computer into a server to provide services over you network. You won't even need the Mac OS X Server, just the Mac OS X Client, so there is no extra software to buy, just the Mac Mini and it's operating system.
This video tutorial from FreeMacBlog and MacMiniColo will show you how to monitor bandwidth usage on your Mac Mini server. This is a short tutorial, but is important for anyone using a Mac as a server. Find a free program that will show you how much upload and download bandwidth you use in a month.