Ok here is a human character (female) that I have been working on for a while
I know it isn’t the best… that is why I put it on here. 
Please tell me every spot that could be… improved…
Hi Sonic14,
The first thing I would recommend is to study anatomy as much as you can. There are many anatomy rules that apply to the head that will help you get the correct shape, proportion and features. One brilliant book in particular is Atlas of Human Anatomy by Stephen Peck: http://www.amazon.com/Atlas-Human-Anatomy-Artist-Galaxy/dp/0195030958
Currently you are definitely on the right track but have a ways to go. Before critiquing the individual features, can I see a wireframe of your model? Along with anatomy having clean topology is also very, very important for creating a realistic head. With clean anatomy comes the ability to easily add or modify details.
Ok here is my human head in wireframe mode. The pictures in the first post had a subsurf modifier with a view of 2. these only have a view of 1.
Oh yeah, these pics dont have eyeballs either.
I’ve made a couple of corrections on the side view regard the 6-pole and two edge loops that can be gotten rid of without impairing the quality of the model.
Attachments
Hi,
OK, a few pointers as to parts to work on:
The eyebrow ridge appears to have a curve back towards the edges of the face. Viewed from the side, the eyebrow ridge directly above the eye is flat with the eyeball.
There should be cheekbones. You have the face running basically directly from the eye to the jaw, with only a single smooth curve between. Actually, there is a bone in there, so you get a ridge of bump below the eye, then the cheek itself.
The jaw is also merged into the cheek, especially back towards the ear. Run you finger across your own face, and you will find a distinct step where the jawbone stops, just in front of your ear.
The eyes/sockets are generally too large for a realistic head, but that may be choice.
You need to model eyelids. Eyelids are not smooth extensions of the cheek/eyebrows that just happen to meet the eyball. They are thin foldable pieces of skin, which fold away into creases when they are opened. Exactly how they do this depends on the ethnic background of the person, amongst other things,- some people have a large bulge between the eyebrow ridge and the eye socket, and the lid slides underneath this, others have no bulge, to the eyelid simply folds into itself.
The bottom of the nose meets the face at too oblique an angle viewed from the side. This makes it seem mashed into the face. It generally meets at almost 90 degrees.
The inner parts of the eyebrow ridges are slanted downwards, giving a permanent angry look.
The nostrils need to be wider. A general rule of thumb is that they are as wide as the gap between the eyes.
The upper lip needs to smooth into the face more. There is rarely as sharp a break between the lip and face as you have. You also have some strange topology in the mesh around the nostrils/lip area. The edges from the nostril area should pass down towards the edges of the mouth, rather than straight across the face. This may be what is causing the ‘duck bill’ look of the upper lip.
The neck is not a simple tube. It has a central tube ( your throat) with two angled blocks of muscle either side. Merging into these side blocks are two muslce groups coming up from the shoulder joints.
A suggestion for modelling any organic item is to not model the whole thing, but to make a small mesh to model each bump, or feature, on it. This forces you to stop seeing the face as a single entity, and makes you see each muscle, or bone, or fold of skin. Make the mesh follow the folds, or the bumps, or whatever. THEN you join them together. The result may be messy from a general topology point of view, but it will be more accurate, and will teach you to look at what you are modelling, rather than assuming that you know what shape it is, which is the commonest problem with any form of art. You can always retopo the final mesh to make it ‘better’.
HTH.
Matt