In this really easy to follow tutorial about edge loops Athey Nansel-Moravetz explains how to go about designing your characters to have good edge loop integration. The idea being that you will be able to create guide images to load into your front and side views in Blender and build your mesh to suit the design.
Here again you can see a nicely planed edge loop layout in this body for a Street Cop in this tutorial by Mashru Mish. He has evenly spaced the edges and kept the joint quads divided at the bend these are the key edges. Also there are support quads and edges called fills that are closer to the bend. These are placed around the key edges in order to stop deformation flowing too far up or down the leg and arm joints.