I think it looks really good! There are only a couple of things that I saw to fix (looking from a photo that seems close to the angle as yours):
1) The neck looks a little thin, but widening that is no big deal
2) Neck is a little long
3) Bring the back and rump up more to deal with the neck issue
Taking out my tablet and doing a quick redline over the doodle to say what I mean: Imageshack - 74538168570882942514387.png
As for the shading, looking to a reference photo is the best advice I can give. First shade in the lighter features then go in and shade the darker ones in.
*edit - the line over the eyes is just so I could see its angle relative to the nose. The eyes look awesome!