Hello,
I'd highly recommend Vilppu's drawing manual and "Figure drawing - design and invention" by Michael Hampton. First book focuses mostly on shapes and dynamics in the pose, while the other focuses highly on anatomy: proportions, how to think, what to look for, muscle groups everything you need to know, how to draw them and how to think about them. Both are life saving. I mostly work digitally but I think I'd recommend pencil and charcoal. Charcoal mostly to make sure you don't get caught up in detail, or, the opposite - to make some shaded drawings.
I'm not an expert but seeing this thread empty made me think that might be of any help.