Wow, that's actually really good for the first time you've done a head! The topology (edge flow) isn't too bad, but as noted, it does need some work. Maybe it's me, but a head is quite beautiful when in wireframe mode
I just like how you can see how the edge flow loops around in both directions. Around the face, and around the skull.
I like to start from the nose and move my way back, using symmetry of course. For some reason, I like imagining that I'm stretching a balloon like material over his nose, progressively touching the rest of his facial features, and then wrapping it around the back. Once this basic shape is down, I imagine that I'm just using my hands to press on the front of the balloon to reveal in more detail his cheeks, lips, eyes and nose.
The eyes are also done separately. Just leave a hole where the would go and add them in later.
"If I have seen a little further it is by standing on the shoulders of Giants" - Isaac Newton
-Degrees: Computer Animation-