As mentioned, a good set up requires both know how and the right tools, as well as a good place to do it. Normally the tools are fairly simple, hex wrenches, screw drivers, gap guages, needle files and of course a very accurate tuner (strobe recomended.) Tools you can't buy are a good eye for detail, a good ear which can recognize the smallest variation in pitch, and a lot of patience. Some guitars are simply a lot harder to get "just right" than others.
If you really want to learn how to do it for yourself I suggest you take a couple of your favorite guitars to a pro and have them set up. Watch carefully to see what is done, and in what order. Ask questions about each step including what can happen if this is done wrong. Start with your least favorite guitar (you wont hate yourself as much if you don't get it right) and try to do what you saw the pro do. Don't get discouraged if your first attempt dosen't go as smoothly as the pro and it still sounds a little off, by the time you mess up a couple of hundred you will get the hang of what you are doing.
I'm not trying to discourage you, in fact with as many guitars as you have I would strongly encourage you to learn to do set ups for yourself. There are several of us on here who could "walk you through it, step by step" but to set down with a pro and have them tell and show you will give you a better understanding of what needs done and how to do it.
If you want to try it, and learn from some of us.... go ahead and put on a fresh set of strings and stretch them and let us know, then we will go on to step two.