It would be good if he practiced things like figure drawing/ life studies and learning things like color theory, perspective, and anatomy. Also I'd recommend going to the library and getting some figure drawing and anatomy books for him to learn out of, they really helped me when I started drawing seriously.
I guess to start, my name's Kelsey. I've been stalking this site for a while now, and since I have summer break I've been crafting like crazy. I mostly sew and make jewelry/charms, I also draw and paint a lot. : D