Hi rsbrash,
Although you could learn a lot by reading the articles and forums here and at other websites, nothing beats hands-on experience and having a curious mind.
If you have only 1 PC now (either home built or store bought), my suggestion is to build yourself another PC (if your finances allow). It doesn't have to be a high end dream machine, just a simple rig that you can "play" with and use to get familiar with all the components that make it work and to maybe "play with and learn" different operating systems and software applications.
Taking classes is good, but will only take you so far. There's a big difference between "book smart" and actual hands-on experience. Most of what I know about PC's comes from learning this stuff on my own. I've only taken software "classes" that my job sends me to. All hardware related knowledge I have comes from first fighting to upgrade a Pentium 100MHz Packard Bell, then putting together my first PC (much easier to upgrade), then putting together PC's for friends and family (with the accompanying calls for help) to finally owning several PC's that I "mess" with. I learn the most when I'm experiementing with my "bench machine".
And I spend a lot of time here reading the threads where a problem is presented, ways to resolve the problem are offered, seeing that some suggestions work and some don't, and finally the fix is found and the machine is repaired. It's really interesting and I feel time well spent. Plus you can pick the brains of some very knowledgeable people here.
But I honestly believe you'll learn the most by building your own PC and maintaining it.
Cricket