By the way, if anyone has been intimidated by circuitry, or just wants to dick around with resistors and stuff, I cannot recommend Falstad Circuit Simulator enough:
From the absolute basics to as far as I am now, this funky drag-and-drop system has helped me understand circuits better than building it in person has. It has a great visualization for how the voltage and current flows, and you can get a graph of what's going on anywhere at any time.
Also, for the young'uns, this I would say is the best of what the pre-corporatization Internet had to offer, and you can absolutely check it out as a museum piece. There are no cookies, there is no account, there are no ads. Some guy Falstad makes fun simulator applets in their free time and puts them up here.
Oh, and because it's a Javascript applet, you can download it and open it as a file