Kazu Kibuishi is the comics creator who makes Copper (and other comics). In this three-page tutorial, Kibushi gives us a detailed look at the process of creating a comic from pencilling to inking to coloring, with great photos and descriptive material.
(Thanks, Zach!)
Update: Kevin points us to this explanation of how an issue of the AppleGeeks comic gets made — it's a noteworthy study in contrasts.
Update 2: Here's a great comic describing how a comic in India is created — thanks, Avi!