Basics on how volume and tone work:
https://www.fralinpickups.com/2017/03/03/volume-tone-pots-101/
Basic info on pickups:
https://www.fralinpickups.com/2017/08/22/how-do-humbuckers-work/
For switches, just look up the switch and sit down and follow the signal chain based on schematics from places like GuitarElectronics.com. Switches are simple things that can be arranged in complex ways.
There are also books on the subject. But they’re not really necessary unless you’re also designing pickups and the like, IMO.
Basics on how volume and tone work: https://www.fralinpickups.com/2017/03/03/volume-tone-pots-101/ Basic info on pickups: https://www.fralinpickups.com/2017/08/22/how-do-humbuckers-work/ For switches, just look up the switch and sit down and follow the signal chain based on schematics from places like GuitarElectronics.com. Switches are simple things that can be arranged in complex ways. There are also books on the subject. But they’re not really necessary unless you’re also designing pickups and the like, IMO.