Does anyone have a complete guide to gearbox construction and differences within them?

Hey everyone! I’m a rising sophomore on a robotics team that is on the smaller side, at least when it comes to experience and the ability to teach. I’d like to be more of an expert for the upcoming season, as I feel that last year I wasn’t able to learn as much about construction as I would have liked too. Specifically I want to learn about the drive train and it’s construction, but any other tips one may have for the upcoming season is obviously welcome. Thanks!