Hi, lovecastle:[link] reference photos of humans, big cats, horses, hands, heads pixelovely:[link] reference photos of people and animals Zvork Virtual Lighting:[link] interactive lighting on 3d human models
There is a section in Bridgeman's book which teaches how to draw heads in perspective. You can do studies of the drawing in that section of the book as well as read the notes he makes. There is also Loomis's method(in the book Drawing Heads & Hands) of drawing heads which works really well with dynamic angles. Here is playlist of videos teaching and demonstrating Loomis's method for drawing heads at various angles. [link]
Well everything can be broken down into geometric forms, including the brow, nose, eyeball and mouth denture. Again this is discussed in detail with Hampton's book . If you are just looking for reference, get a mirror and start sketching(best reference ever).
Yeah that would be harder for poses looking away from the viewer. I will just search some images on my own and look at my books, I was just wondering if there was a site that had a lot of organized ones to view from.