This can be convenient for installing updates, new OS's or performing diagnostics/repairs. My process of accomplishing this will, as often as possible, use the GUI utilities available. Much of it can also be done using command-line instructions, but in my opinion, leaves too much room for errors.
I'm definitely not the first to accomplish this and without the information from others that have, it would have taken me forever to figure out. Nor am I attempting to steal the glory from others that have published processes to do this. While most of this information is available elsewhere, I am attempting to put it all in one place and make it possible for less experienced users to accomplish. Direct references to all of my sources will be in the last step of this Instructable.
Also, be sure that you have a license to support any OS or software that you serve to cover all the computers on your network.
Step 1: The Network
Only computers connected directly to the network through Ethernet will be able to boot off of the network. Computers that normally connect with a WiFi adapter (Airport) will have to be connected physically with an Ethernet cable before using the NetBoot facilities.