It all depends on whether or not it's sealed or not. If it's sealed with a polyurethane or drying oil like tung oil (Waterlox) then you don't really need to treat the wood at all. Mineral oil or wax would not penetrate the surface. I would just wash with mild soap and water. Maybe spray some furniture polish on it from time to time to make it a little more shiny.

If, however, it's sealed with mineral oil or beeswax like a cutting board then I can offer better advice to you since this is our specialty. We have a lot of information on our site for cutting board care. http://www.sawedoffwoodworks.com/care-and-maintenance/

You must keep the wood oiled to prevent water from soaking into the wood. Mineral oil is the tried and true traditional stuff. Pour it on and let is soak in until it won't take anymore. Wipe off the excess. When it starts to dry out, oil it again. However, we find that an oil/wax paste is far better than oil alone. It stays on the surface longer, protects better, and leaves the board nice and shiny. There are many brands out there (including our own Clara's brand) They all basically do the same thing. ...but ours smells better because we added citrus oils to the mix. :)