If you wanna draw people too, well here's the gist of it.
This method can grant you the ability to draw a human character in pretty much any position desired. Think of it as a multi-toolkit, by your side. I much more perfer this method over that damn "head measurement" method. (Immitate's a retard's voice: The man's body's 6 heads, the woman's body's 5 heads, the kid's body's 4 heads, dee deedeee~!) I'm sorry, but in my personal experiences and studies (even in most anime styles), just about every body type is proportionate to its torso. The head actually changes in size depending on height. (Proportionately to the body, taller = smaller head, shorter = larger head.) That can justify the "head measurement" method to be valid, however, the bodyparts are almost always proportionate to the torso. Not to the head...
Anyway, back to the guidelines.
If you decide to practice training your drawing hand with these guidelines, go as far as knowing them by heart. After that, don't use them again unless you get very lost. Remember, the guidelines are meant to help you feel and see the full degree of movement, angles, and shapes of the body. It is not meant to replace your drawing style. If you allow this to happen, then your style will probably become a bit distorted and you might get a bit confused too. By focusing too much on having your drawings precisely match the guidelines down to a tee, your own natural drawing rythm could get thrown off. Then you might not be able to notice it because you're focusing too much on the guidelines, and then you might get a bit frustrated because you can't quite put your finger on what's wrong. (That hapenned to me...) The cure to this is: If it feels right, then you're probably doing it right.
Remember, all you're doing is tuning up your drawing style. The guidelines are just "training wheels" on a bike. When you're comfortable enough to ride on your own, just ditch the training wheels and confidently burn rubber with your own style!
HEAD
NECK
TORSO
LEGS
The rest of the bodyparts will be up here in due time...