Gallery collections are usually hit-or-miss, but this one lands right on target. People just interested in the female form will find exactly what they want, but it's awesome for serious artists as well because it shows the original pen-and-ink sketches that later turned into the finished CG artwork. The poses range from serious to playful, dramatic to posed, and feature models in every state of dress from fully-clothed to wearing nothing but a smile.
A very nice gallery of nearly 200 lower-resolution PNG images. Kudos to the uploader!