I have 2 aa boys with different texture hair, and one dd. I agree keep it short, but not all the way down to the scalp (prevents hair bumps) a little bit on top, and a slight fade in the back is very cute on small boys. Use a little bit of natural oils (jojoba, almond) try in a small spot to make sure he does not react to the product. Do not worry about the sheen, or how his hair curls, as long as the hair is kept pliable. Use a wide tooth comb or a pic after his bath to comb out his hair, if it is short use a boars bristle brush to keep it brushed. (soft bristles) React positively to his "curls" and this will encourage him towards spending the time to groom his hair later on, and like who he is. Please do not use vaseline, it clogs the pores, and attracts dirt to the hair. Most blacks do not use such products anymore (I am aa)
Best wishes, and try sites such as this for your resource.
Natural Black Hair Care
specific to children
Natural Black Hair Care