I learned what little I know by just doing it, as a kid.
We used to take our bikes apart on the patio, laying the pieces out in order to make sure they at least went back in the same order. We'd siphon gas out of the family car (we had an electric lawn mower, no gas can) to use as a cleaning solvent. It's a wonder we didn't burn ourselves to a crisp. Back in the single-speed coaster-brake days not a one of us had the faintest idea how to tighten a cone nut against a lock nut. We didn't even know what a cone wrench was.
With age and experience came a little wisdom, and by collecting and reading bicycling books I acquired a better understanding of theory and techniques. I never got much beyond the basic skills needed to overhaul and adjust. In other words, I never got into anything having to do with the frame itself, and very little in the wheel-building and truing department. Vintage bicycle maintenance seems pretty simple to me, although I had friends in college who seemed to think overhauling a freewheel was right up there with brain surgery and rocket science.
This leads to an interesting observation. When I was younger I didn't seem so daunted by a lack of knowledge. I just plunged in and got my hands dirty, and usually did things wrong several times over before finally figuring it out. The older I get the more I tend to talk myself out of trying something new, for fear of messing it up. A case in point is my off-topic (shhh!) bike. I was never so disgusted with myself as when I took it to the LBS. The only salve to my conscience was that they actually fixed it good, cheap, and quick.
So, (speaking to myself as well), the first thing is to turn off that little recording in your head that says "you're going to mess this up". Don't expect to a new task to come out perfect the first time. Expect there to be a learning curve. Having the desire is the key. If you really want to do it yourself, you can get there, maybe easier than you think. And of course, think of the tools you can justify buying because of the money you'll save on repairs!
On the other hand, if turning nuts just doesn't interest you, don't feel guilty about it. Or, to use a phrase from your generation, don't let anyone lay a heavy guilt trip on you, man!
John Hurley
Austin, Texas, USA