Rigging for character animation? It's pretty complex in an actual production suite. It involves setting up all the joints and their hierarchies (ie shoulder > elbow > wrist > knuckles). For each joint, you need to punch in the degrees of freedom (whether you want a ball & socket / gimbal / slide joint), their tolerances, thresholds, etc. When you are simulating muscles, you have to include tensile/torsional/compressive tolerances as well.

My 3D graphics class wasn't a workshop/studio type class, we didn't use Maya or other apps, we learned the algorithms/theory and had to code our own basic skeletal engines and such. It was just a huge list of forward & reverse kinematic tree elements and their respective values. We animated them with a basic keyframe & interpolation system.

In any case, I did a quick google and there seems to be a few good online tutorials out there. But if you're old school like me, a good Maya character animation textbook will do even better.

...I'm sure he could do it if he had the materials.