In your front viewport move the points of the eye radial so that they fit to your drawing. Then in your shaded perspective view pull those points one at a time in the Z direction until they ride the surface of the nurbs sphere.
These points will define the eye lids of your head. The next thing your going to want to do is create another radial around the lid to help define that shape a little more.
Grab the verts of this radial and push and pull them in space until you get a good looking eyelid.
Our guy is still a little rough but he's shaping up quickly. It's good to work as light as possible to define your shapes quickly. Don't go overboard trying to add in detail... that will come later. Right now just concentrate on creating the form of the head.
Next thing we will work on is the nose. To start out, draw an edge starting at the upper lip going straight up passing through where the center of the nostril will be and continuing up into the forehead.
As you add in new edges, you should push and pull the points to define your shape better and make it rounder.
Next, we will have to create an intersecting edge to create a point that will define the center of the nostril. Start the edge at the beginning of the upper lip and carry it through to the bottom of the nose. When you run an edge to define a point of detail, always try and run it so that it conforms to the natural flow of the face. Think of the way the muscles and folds of skin flow and try to run the edges that way, this will help you define your edge loops. Notice how I run mine so it follows the natural curve of the face.
Also keep in mind that when you draw these edges you are trying to stay directly between your two outer edges.
The next step is to start to draw in the radial of the nostril. Draw a diamond around the nostril center.
Sub-divide the nostril just as you did with the eye so that you can make it rounder and give more detail to that area.
Then push and pull these points to define the nostril a little better. Notice I'm not adding too much detail to these areas before I move on to the next area.I'm just defining the shape a little, then moving to the next area that needs a little more definition. The reason for this is that if I need to rearrange the direction in which my edges go later... it will be much easier to do with less detail.