Is the wood raw? You can wash it up then sand the rest off.
Try a little baking soda on a damp cloth. Rub lightly with your finger.
Hi Annie: Give WD40 a try. Spray some WD-40 onto the marks and wipe with a clean rag. WD-40 will not damage the paint or most wallpaper (test fabric or other fancy wall coverings first). It will also remove marker and crayon marks from furniture and appliances. Good luck
if the wood is raw, just sand it, if it finished try olive oil, or any of the above methods :)
magic erasers are miracle workers!
maybe they can help..