The Skeleton is very complex but at the same time its only 206 bones. Like anything else when you don't have a strong understanding you will most likely struggle with it. It is strongly recommended that the time is put in for any serious artists to learn the bones, not all 206 bones are necessary but the more you know the better it will serve you when it comes to drawing them.

A good way to start is with the simpler more popular bones, like the ribcage and hips, arms and legs. The body has certain landmarks that can help you start a drawing, these landmarks very but for the most part, they are noticeable on all people. Below are a number of images from Roberto Osti Basic Human Anatomy book. This book has rich images and in chapter 3 he focuses on labeling the bones to a great degree. I Highly recommend this book.

All Images taken from Basic Human Anatomy by Roberto Osti