So you've already gone from nurbs to polys then? Your dog looks like it's still in nurbs?
With non manifold geometry, look up in the help file the 'cleanup' command. It can help to point out where the geometry is, and sometimes it's pretty good at fixing it (others not so much...)
With lighting, have a look around at "3 point" lighting setup. It basically consists of one light to one side and above of the camera - your main (key) light. To the other side, a secondary light (fill) to add some ambient light to the shadowed areas that the key light doesn't hit. Above and behind goes a back light (or rim light) which highlights the silouette of your character.