For a hiking trip you need to have socks that will wear well over time and keep your feet dry. Any camping store will carry this type of sock. If you are hiking a long distance it would be good to bring more than one pair.
Invest in a few pairs of Under Armour brand socks. You need socks that will cushion your feet and keep them from getting too wet with sweat. Under Armour are specifically designed for this type of activity.