Personally, I do agree with Asteroth. Next, it looks like you've tried your hands at using subdivisions. I will state that you did better than many other people I've seen, but the model is still pretty sloppy in some areas. Furthermore, I assume you've got an unnecessarily large polycount on that model because of the subdivisions.
To repeat what I've said to others, there's nothing wrong with subdivisions, but like any tool, they have to be used responsibly. In that sense, I think you've got a bit further to go in your modeing skills before you can do that. I'll note that I've still not reached the point of using them myself in a truly effective manner.
