Try to search around and find a good simple explanation.

A good simple explanation doesn't tell you which way the pilot valve moves or all the intricate parts, it focuses on the concepts and basic operating principles.

Governor employs speeder spring and flyweights. Flyweights help to maintain constant RPM by adjusting oil flow to and from the hub. As prop slows down or speeds up, flyweights move in or out, allowing oil to flow to/from the hub to adjust the angle and keep the speed constant. Think about it like a fixed pitch propeller and what that will do if you pitch up and down, then think about what the constant speed has to do to avoid this.

Speeder spring keeps tension on flyweights and allow you to set RPM settings. If there was no speeder spring, the flyweights would overpower and the prop would "stick" at one extreme setting. This basically allows you to set the "point" that the prop will try to seek out when it experiences something that slows it down or speeds it up.

Nitrogen usually (in a twin) is used to pressurize the hub and is working against the oil pressure, it's trying to feather the prop. If you lose oil pressure, this is one of the reasons why it will feather, the nitrogen will push the oil out of the hub and twist the blades towards feather (but the counterweights and aerodynamic twisting force are important too).

This isn't the best explanation I'm sure, but be wary of complex diagrams and explanations. I didn't explain which way the oil moves (except for out of the hub when it feathers) or whether the flyweights get closer or further on purpose, because I don't think that's critical to understanding/describing the system and being able to competently operate it. I can explain that no problem and I've honed to a T drawing complex prop diagrams...but in the end I don't think it really helps much. I'd be happy to describe some specifics if you like (tomorrow though).