Red lines...hope its fine with you.
First off, I'm guessing you're still new with drawing?
You do have anatomy and proportion issues, i suggest you practice more with that.Use lines to serve as a guide; specially with the face, it helps to know where the eyes should fall.
In the pic above, remember that the arms don't stretch all the way to the knee and should only be up to about half of the thigh.
I suggest you use the mannequin (im not sure what its called) style of drawing with bodies or use stick figures as guides...what you need to know is to understand the right proportions and body lengths of a human body (like how long the shoulder or arm should be) There are lots of anatomy tutorials out there that would help you.
As with the hands...yes, they're a bit tricky to do, but i suggest you start off with basic shapes as guides like what i did above.
Best advise i could give you, PRACTICE more! and search for a lot of tuts around the net, I could teach you but that would take me long
xp (and im a bit lazy...)
well, hopefully what I said made sense.