For the typical small business, the real cost of the network is in the physical wiring.
If you want it done properly, you will run your wiring through the walls. The network wires will terminate at your employee's desks with jacks that are properly mounted in compliance with your local building codes and the National Electrical Code.
The other end of the cables will run to a wiring closet or some other out-of-the-way place. These cables will be connected into a patch panel. A patch panel makes it much easier to troubleshoot cable problems or to switch connections at a later date. Sure it costs a little more, but it is worth it in the long run.
Then from the patch panel, you connect all the wires to a switch to enable network communication. Switches vary in price based on the speed of the switch and the number of ports.
All cables should be properly terminated and tied in an organized manner. All network equipment should be either rack or wall-mounted with at least 2 inches of clearance on each side for proper ventilation. This will extend the life of your equipment.
All network connections should be properly labeled on each end of the connection! This will make repairs easier if there is ever a problem.
If you are cheap, you can always run wires along the floor where people can trip on them. This is dangerous and I don't recommend it. I once saw someone trip on a network cable that caused a computer to fly off a desk and crash into the wall. It takes only a few minutes to tie up loose cables and get them out of the way, so buy some zip ties!
When budgetting for a network, make sure you know how many "drops", or connections, you will need. Since wiring is a labor intensive task, go ahead and throw extra cables early on. If you plan to grow within in the next year, include those drops in your plans.
An experienced network designer can help you reduce your costs when designing a network. Make sure you work with someone knowledgeable not only in network design but in all the applicable sections of the National Electrical Code and your local building codes. Remember to overdesign your initial installation so you can grow into it later on.
Read more! Choose from the rest of my "Where's the Cost In...?" series: