If I were doing this for commercial purposes, of course, I'd most likely buy a membership from a stock photo/clip-art site and pay a large sum of money to download a couple of measly images that I don't even know will make it to the finished product. Inevitably, I'll have to do this one day if/when I go pro, but until then, I'm always looking for more affordable ways to pursue my hobby.
And then my friend Celestine gave me a recommendation for a website called MorgueFile. It's got a pretty weird (possibly morbid) name, but it turns out to be an excellent source for free and legal stock photos for just about any use possible, like for educational purposes and commercial purposes! (YES!!!)
As you can see on these covers, I've incorporated a lot of MorgueFile photos into my covers.
So now, this is great. I've got a wonderful resource for legal images, but I've still got one other hurdle to jump over. What about legal fonts? I'll discuss that next time.