So I finally found the simple Windows Movie Maker that's already on my PC. It's actually pretty easy to use and customize. I would recommend it for anyone trying to make something like a book trailer if you have good images & a great cover. You can then get the music at a few sources. I got mine at audiomicro.com and it wasn't too expensive. Considering how much it costs to get a book trailer made when you get a pro to do it, the DIY cost is minimal here. The extra graphics in my video that are not from my cover somehow are from Dreamstime.com. I bought a subscription plan a while ago and can download 25 pictures a day. I don't really recommend that for someone doing one video, though, because I'm finding that I am not downloading pictures, and so a lot of those days go to waste. Just buy a one time something because you don't want too many pictures other than your cover in your video.
Anyway, that's the DIY details. And here is my gorgeous video, which I am very proud of.