A lot of people have been asking for this, so I just made a small basic coloring/shading tutorial. I hope it helps someone ^^

Alternative to "Color Dodge" if you're using SAI is "Luminosity", you can also use "Overlay" and just experiment with opacity and colors.

I also wanna add that the shadow and highlights colors depends on the light, if its like rainy weather it would be blue or purple in color, if in a forest it will be green as light bounces on the leaves and hits the subject and so on, just play around with color and experiment see what suits the artwork best :)