I had a TON of notes on Arms and Hands, and fingers. I grabbed what I thought was most important for this tutorial. It was a pain in the butt to place things in some dicernable order, so I hope it doesn't confuse!
Thanks for posting this. Hands take a lot of practice, but it's something you need to learn if you want to draw. That goes double if you want to go pro. I heard that the legendary Jack Davis got where he is today because he was very good at drawing hands.
As much as I enjoyed this and think it's a good reference, the "Arms and Hands tutorial" name was a bit of a misfile. This shows how arms move and the anatomy of the arms and shares quiclk tips on making them accurate, but doesn't teach you how to actually draw hands and arms. That said, I can not deny that if you have an idea of How to get past step one, this is a map to the end product and is full of tips and tricks.