@Pixel: He added more to the side of the head.
@Shadowcast: That looks a lot like my first DBZ model did when I started it. As a tip, you're going to be hit hard with crits from the other modellors here if you keep that gridlined style and start with the face, cause you'll have huge problems with the back of the head later.
What I'd do, is start out with a whole head, by starting with a box with one division down the center, and two divisions across horizontally. Then start using the vertices to create a VERY rough example of the shape, and then add detail as you go. That way, you already have the back of the head. It saves a lot of time.
Also be aware that your model will take a LONG time to make, at least until it's correct in the minds of the modellors here (the serious ones anyway). I started my first one at the beginning of summer, and its STILL not finished because I have to keep remaking it. Polyflow is a B**** to understand too, so expect this to be a long and grueling process.
Good luck man. Oh, and for further information on that technique, look at the "mass-blocking" video tutorial on " poopinmymouth.com ". It''l give you a basic idea on how to set the beginning vertices.