Zbrush Hand modelling complete process
Good reference on how to block out characters. Remember, if your taking more than thirty minutes to block out what you're doing, you're going to be taking too much time.
Soule Designs - Skull studies
Sakaki's SketchBook & Video - Page 2
Great 3D model process shown here. It's helpful to look at this and see the transition from basic shapes into a highly detailed mesh.
Free Fur Brushes, jarred everson on ArtStation at https://www.artstation.com/artwork/1WB03
ArtStation - Mouse, Paul Deasy