Conditioning Your Cutting Board to Last
Once upon a time your wooden cutting board was alive, in a forest, a growing tree or bamboo plant. Its a natural material that maintains some of its living characteristics. Wood changes, and mostly degrades as it gets older. You can help it look its best and last longer by condition your wood cutting board with oil. The oil rub down prevents bacteria growth and resist lacerations in the wood.
Pour 1/4 cup walnut oil or common pharmaceutical mineral oil (cheaper) on your board and rub with a cloth over all sides, top, and bottom. My father's pours the oil on the board and lets it sit over night allowing the board to absorb the oil where it needs it naturally. Let sit for 6-8 hours. Wash if residual oil lingers on top.
Thanks to Food2.com for re-posting this information.