This post is a list of the handiest articles about Drupal module development I've found on the web. I think they should be considered "required reading" for anyone interested in making great modules. Some of them are just links to APIs regarding useful or insightful functions, others are full tutorials.
I've been reworking parts of the model. The face has been improved, and the chest is no longer a bunch of cheesy, extruded rectangles. The green lines are edge loops that are defining the musculature. I've been trying to follow the general rule of avoiding triangles and sticking to quads.