Not a bad initial sketch. Already though, the shadows (blue) don't seem quite right. The forehead looks strange (almost gives the impression of a lump on the noggin), and I think the left cheek needs to be re-shaded. The shadows give an impression of an oddly shaped cheek in my opinion, though it may clear up anyway, when you define your sketch further.
I feel the hair is quite well sketched, and I'm interested in seeing how that'll progress as you work on this piece.
You may also need to be careful with the left eye as you further define the work. It's a little difficult to understand what's going on with it now, and that could get worse as more detail is added. I think he's squinting the left eye, but I'm not entirely sure. It also looks a little like the eye may be injured instead. As you progress the piece, be mindful of what the eye is supposed to be conveying, because it has the potential to become more obscured later.
Can't wait to see how your next iteration of it looks.
