First off, nice progress. Definitely a good starting place for your first box modelling.
Okay, you've got your edge loops in there, but your not really doing anything with them. There aren't really any cheeks, the jaw mushes into the bottom of the head and neck, and the loops you have going around the mouth start at the wrong place, and you don't need that many to boot.
- The polygons that circle the mouth first start at the nostrils, and then loop around the lower lip. You've got them starting at the bottom of the nose, which throws the entire lower portion of his face out of whack.
- He's got no jaw because you've become obsessed with making edgeloops!! Remember, You only need them at the eyes and mouth, everywhere else is fair game so long as your polygon's are almost always four sided. (Of course if you can figure out how to keep lots of edgeloops and still define a jaw, go for it)
- His face looks kind of flat. That's probably because you have a a pretty sharp turn between the front and and side planes of the face.
- His nose isn't properly defined. I mean its there, but the bridge of it is kinda of blending into the face.