This site has a nicely written bit on why the various parts in a controller are in a controller. Like, why does it have caps, what do they do? What happens to the current/voltage etc when inductive effects come into play? What really makes the FET's get hot in a controller?
Etc etc, and the guy writing the stuff actually has real-world experience with doing controller design in the >~100amp range.
He does a good job of explaining a few fairly advanced effects (induction etc) in a way that makes it simple, he is a lot better at writing than me. lol