First of all - step away from the server room, Now take a deel breath. Now take another one.
Forget wireless. Zertz has already pointed out the benefits and the last thing you need to do is add complexity.
The first thing you need to do before you go running around changing things is to determine exactly what you have.
"3 servers, a router, and what looks like a switch board (I am assuming that is the thing with a bunch of ethernet style cables running off of it) also, we have a DVR security system and 2 monitors (one is for the dvr security), also in the back we have several external hardrives just sitting around plugged in and in the front a little walgrees style fan blowing directly at the server tower."
That's not very specific. Let's start with the servers. What OS are they running? Are any of them running a true server OS? What function(s) do these servers perform?
You mention a router. What make and model and how is it configured?
A switch board? Is this a switch or just a patch panel? We need more info.
Whats on the network - "12 or so computers" - be specific and also identify any other devices on the network such as printers.
The next step is to draw yourself a basic network diagram. This will help you understand what you have and make it easier to visualize.
I'm also concerned about the "several external hardrives just sitting around..." Are they being used and if so, what for and how much data is on them and to which machines are they connected?
Now, you've asked about NAS devices here and in your other thread. The benefits over a single external drive are numerous, but chief among them are:
- Greater flexibilty
- Allows for shared access across the network
- Allow greater capacity and you can expand capacity as needs grow with volume expansion
- Some can be used as depositiry for security cam recordings
- Can be administered through Web interface
- Built in security
The only drawback is cost when compared to a single external drive.
As for backing up the 12 computers weekly - they should be configured to store all the data on the servers and not locally and then you can back up the servers on a nighlty basis.
This just touches the surface, but at this point, you might want to consider what Zertz asked and decide whether you want to get into this until you have a lottle stronger knowledge base.