I like the large size of your drawing and the shadows you've added with (charcoal?). The muscles along the spine are coming along very nicely.
Before you start shading, make sure your proportions are accurate. The feet are too small and the hands are not rendered yet. If you struggle with those, I suggest practicing gestures in the 'hands and feet' category.
Adding details before you have solidified your sketch into a proportional and accurate form makes it hard to see the mistakes underneath. Shading can be implied on a gesture with a quick mark using a flatter/wider side of the medium you are using. I do not suggest shading or adding details like hair until all the structures underneath are correct.
Best of luck!
Thank You NC TiffanyArt!
Your criticisms and comments were well thought out and constructive. i will strive to use your advice and improve. Please continue to watch and comment in the future. Any constructive critique is greatly appreciated.