I have messed around with electronics for a long time, but a lot of it is still a mystery. So, I was thrilled to realize that free, online circuit simulators exist. My favourite one is http://www.falstad.com/circuit/ . It gives examples of dozens of circuits, you can modify them, or you can make your own. Better yet, no login required, if you want to save your work it will spit it out as a text file you can import again later. Thanks, Paul Falstad & co, for putting this together and hosting it!