I never had a class teach me how to build bones, rig or skin a character. I've always relied on youtube tutorials and the like to teach me these things. Unfortunately, there is only so much knowledge that you can acquire from such a source... And while the youtube tutorials were an amazing source of information that pulled me through some decent rigs in the past, I needed something more... professional and in-depth. My 3d teacher told me to seek out these rigging dvds from cg academy - the ones made by Paul Neale. They were at the school library and in 2 days I learned so much about rigging and skinning - even if the information was a bit dated.
This is the 3rd time I am rigging this model, and it will be the last. I am quite proud with the arm bones and their rotation (previously I could not get it to function), as well as the foot controls. She also has "breast bones" so that they can bounce using spring controls while animating... so I have less work to do down the road. I thought it would look strange if they were.... hard as rock. If you are trying to achieve realism, EVERY BIT HELPS. Every tiny bit of movement that lends to the believability of the character is necessary. Living breathing humans are never static, we are always breathing or doing some kind of task. And in 3d, it is even more important that the characters are constantly moving because as soon as they stop, they look unnatural and the illusion of life is shattered.
I am paying close attention to these tiny details (or at least trying to). I have almost finished skinning. I have done skin morphs, however, at some point, they stopped working properly... and so I have to redo them. The joys of 3d. I am also simultaneously working on the facial morphs (and eye morphs) of the character but that is another post entirely.