I do too xp it takes a little practice. just mess around with it. use your finger or some tissue to rub the pencil into the paper and spread it the way you like =3
you can try it on a computer as well =3 look up shading vids. try to find some easy ones.
I usually use a paint brush to add some darker color to a pic. recently I've been covering my pic in a dark color and erasing the areas I don't want shaded. =3
Link
LenGrey
heh heh xp looks good