All day long I have been learning from these fantastic articles on electricity. This website
http://amasci.com/elect/elefaq.html (which has all its articles written completely by a professional electrical engineer) has helped me understand more and more the concept of "electricity" (which by the way does not even exist). I learned a ton, such as how electric current is not always just electrons but it can be a flow of protons or ions, how electricity is never really produced, only electromagnetic energy is which across a circuit which has a current as its medium. Electric charges are always present, a generator just moves them. I also learned more such as how "electric pressure" is not so good of an understanding of voltage, and how current is often misconceived. Voltage is basically static electricity, the static fields that attract positive and negative subatomic particles or atomic particles, just as magnetic fields attract opposite poles.
I highly recommend to any of you to read some of these articles, as they are extremely informative and also state what is being incorrectly taught to kids in schools about electricity. This has helped me a lot in my journey to understand more and more about power supplies.