I get this question all the time at Comic Cons, on Facebook, anywhere anyone sees my artwork. Charcoal is apparently regarded as a very difficult medium. It is a good thing I did not know that until after I had begun using it. I am compiling my answers to those people now to hopefully help you in your journey to drawing with burned wood.
TL; DNR Vacuum your paper and wash your hands!
Charcoal comes in many forms and in many qualities. Pure charcoal uncompressed comes in the original vines (burned twigs) or in actual powder. This type of charcoal is much softer than compressed charcoal in pencils or sticks so it crumbles easily, does not stain paper or adhere to paper as well as pencils or sticks, has a lighter shade when applied to paper, and is easier to spread over large surfaces. Compressed charcoal comes in rectangular sticks or pencils bound with wood or covered with clear acrylic. I prefer charcoal pencils because they can be sharpened most easily and I do a lot of detailed work requiring a sharp point. Quality matters with charcoal because I have owned some cheaper charcoal pencils that contained chunks of matter compressed within the smoother powder. The consistency and smoothness of charcoal can affect one's drawing because harder chunks within the lead or charcoal of a pencil can actually scratch or indent one's paper while drawing leaving a scratch in the paper that fills with charcoal differently than the surrounding area. Charcoal comes in different hardness like graphite does: Ex Hard, Hard, Med, Soft, HB, B2, B8 etc..
The softer the charcoal, the more crumbly and the easier to spread. The harder it is, the less likely to break, and the least easy to get on the paper and the less dark the shade.
Charcoal is difficult to use for a few reasons: usually it is compressed powder that crumbles even from charcoal pencils and blows everywhere, it stains paper in such a way that it cannot be completely erased once applied, and it is difficult to clean from surfaces (tables and hands included). Mostly people tell me how messy it is and ask how I keep white areas in my drawing from becoming clouded with accidental smearing. I use several strategies: