Over the past 20 years, model railroading has moved into the electronic age, with the widespread use of DCC, computer control, and signaling. Learn the basics of electronic theory, what all the different components are and what they are used for. Some of the things that will be covered are the wire size for the layout, the different formulas that you will need (how to figure out what size resister to use for dropping the voltage to the headlight), and the tools that you will need to troubleshoot your railroad.