Don't forget...
Bridgman's Book of a Hundred Hands is a godsend for quick go-to reference on hands and breaking down their anatomy.
How to Draw the Human Figure: An Anatomical Approach by Louise Gordon is the textbook we used for my figure drawing class. It's very informative and breaks down each part of the body into skeletal and muscular structures so you can understand what's going on underneath the skin. It and Constructive Anatomy tend to be my go-to books when I need to look something up (Bridgman's book seems to be rather lacking in regards to specific anatomy of the arms, whereas Gordon is a great supplement for that).
Also Mark Simon's Facial Expressions. It's a great resource of people of various ethnicities and ages (ranging from about 20 to about 80) making different facial expressions. It also has a gallery in the back of common things that animators and artists alike may need, such as hats, kissing, and the shapes of mouths according to the sounds they're making (the mouths, not the people kissing).
All of these are easily found on Amazon or Barnes and Noble.