Okay this is my first time writing one of these so here goes :S
I like this very much; I think you've captured the human form very well. It all looks anatomically correct and the poses are very natural and nice to look at.
The only one I have any serious issue with is the second to last, near the bottom? The waist look a little too slim too me, and the shading under the armpits makes the pose look slightly stiff.
However, all the others look really nice; I particularly like your shading style with pencil, it's quite soft and complimentary to the subject matter, but I can still see it being used in a comic or cartoon.
All in all, lovely work, can't wait to see more from you.