There is a lot of advice out there. But its plain and simple you can't draw what you do not know. If you want to draw a reallistic human form you must know what it can and can't do. Also , you must know what the parts look like. If you want to draw anime or a cartoon style its less important to know,but you still must know the basics.

There are many books out there and you will be surprised what we take for granted. Femal and male bone structures are different. But can you name how? Thats where anatomy comes in. Now, you don't need a college level anatomy class. You also don't need to pick up Grey's Anatomy Book. Something Simple as    The Anatomy Coloring Book   is very good.I recomend this book above the other because these are Basic line drawings. You can Learn about lighting and shadows seperately.  Its a High School Level Book. You can find it at Amazon in the used books for like $5.

Now, some tips how to use this. You don't need to do hours and hours of studying and learning what every single bone is named and where it goes. Buy a sketch book just for your anatomy. And for starters just sketch copy the pages. This helps you get a feel for it. Mind you you don't have to do the Organs, but they would help someone doing bloody zombie drawings. Concentrate on bone structure and Muscle structure. Most of theses once would be enough to get the basics and remember thats all you need. The ones that take a little more to sink in. Those you might need to do a few times. This you might find you need to do for the muscle structure on Face, legs and Back. Remember these are for you and not gonna be on public display. So write your notes. \

Example :  Female shoulder slope down. Male Shoulder are Straight.

When you are done you have refrences. When you draw something take a look back and review. Sooner or later these sketches will make sence and you will remember without looking back.

As you go on you will learnmore about the body. There are so many books out there pick one that most interest you. Remember If you have trouble drawing something Study its Basics, and they will get easier to draw.