Well, you will need:

1. A pencil with a bad rubber on its end.
2. Some vaseline.
3. Colour (according to the colour you want your hair to be).

Now, all you need to do is to draw the *outlines* of the character's head + his hair. Then, shade it all in with the appropriate colour, make it really shiny with the vaseline, and then rub it in the right places to give the hair the correct texture and shadows. Then wait for the vaseline to dry and, finally, scan it in. Tada!