I don't want to be such a bastard about this, but you gave me no choice:p
although your not modeling his actual body, but more the clothes on his body i would still keep the anatomy of the body in mind, since i don't have your sourceimages i've painted over your render (sorry )
As you probably can see it's a very crappy drawing, but it's just for form, so you will understand what i mean.
- try to articulate the part between neck - shoulder, shoulder-upper arm etc.
as you can see there is a lot of curvature in it.
-with the legs i would use 1 extrude al the way down and then with the split polygon tool and/or edgeloopsplits to get the detail you want around the crotch, upper leg, knee and so on.


i hope this helped, and good luck

edit; if you post a wireframe of your model then people could help you with edgeflow/ enough deformation in an early stage, so you don't have to solve any annoying problems when your animating.