My in-laws gave me a nice new 19x13 inch wooden cutting board for Christmas. I'd been wanting a larger one for quite a while, and I'm partial to wooden cutting boards. But did you know that wooden cutting boards need to be seasoned before use and roughly every month or so of regular use after that? Wood dries out and needs a good coat of oil periodically.
The best oil to use, in my opinion, is food grade mineral oil (not to be confused with mineral spirits, which is a paint thinner). I have read that coconut oil can also be used, but I haven't tried it yet. Olive oils and vegetable oils become rancid more quickly and should not be used to oil or season your cutting board.
First wipe down your new board with a soft, clean cloth to remove any dust and dirt from the packaging. Then you will want to wipe oil on the board in the direction of the grain with another soft, clean cloth. (I usually just use a couple paper towels for this job).
Once the mineral oil is rubbed in all over the board, let it sit for 5 or more hours. After the oil has had an opportunity to soak in to the wood, wipe off the excess with a third soft, clean cloth or paper towel. If the board still looks "thirsty" or doesn't feel slightly oily to the touch, give it another coat of oil and let it sit for another 5 hours. I had to wipe down my new board twice.
To re-season an older board, clean the board thoroughly. You may want to wipe the board down with salt, baking soda, or white vinegar to sanitize the board and remove odors. Let the board dry completely. If the cutting board has not been re-seasoned in quite some time, it may be necessary to lightly sand the board to remove scratches, deep cuts, and other damaging marks. Be sure to wipe off any dust if you sand the board. Then follow the instructions above.
Be sure not to let wooden cutting boards soak in water. Washing one in hot water to remove food residue is fine, but letting it soak in a sink will cause the wood to crack as it dries.
A good board that has been properly cared for should last you a lifetime. The one above was given to me as a wedding gift 20 years ago, and while I do not season it every month like I should, I do take care to give it a good oiling several times a year. I wash it immediately after use and prop it up against the back splash to dry.