You'd get more responses in the figure thread, but...I've been using Vallejo beige red as a base skin tone. Shadows are done by adding Vallejo saddle brown; highlights come from adding Vallejo light flesh to the base color. Final highlights are straight light flesh.
Model master has a set of skin tones you might find helpful, though I've never tried them. Tamiya is not useful for painting figures.
For oils, I have used titanium white and burnt sienna. Blending these two colors will give you a good range of shadow to highlight in Caucasian skin.
Don't use black as a wash, it's too harsh. If you must use a wash, use burnt sienna. Model master has this in their line as well.
Hair can be done with dark gray with a black wash for black; various shades of brown with darker brown wash and lightened base for highlights; yellow ochre for blond base, brown wash for redder/darker blond; light yellow for highlights and adding a bit of green to the base for lighter blond. Gray hair can be done with a medium gray base, dark gray wash and white highlilghts. .
5 o'clock shadw can be done with very thinned dark blue for black hair, or pastel chalk for most brunette heair. Blonds tend not to show much in the way of facial hair until a good sized beard or mustache is in place.