Know-how is attainable, grasshopper, but you must have the interest to pursue it. Amazing Ribs is a great website for how-to’s and product reviews. If you can follow directions, you can get started.
I have made my own, and they are good, but I’ve found that, for that much effort, a good pre-made rub does just great. Besides, I found that I was always wanting to make enough to last, and if you’re storing it (or using pre-ground spices), you’re losing the benefit of the freshness anyway. I just look for a rub that doesn’t have any (or very few) fillers or chemicals.