Tons of stuff on the web to read, I like to use Mineral Oil on mine.
Here's one site with some good info.
Wood Care
Items made of unfinished, unlacquered wood, such as many bowls, spoons, cutting boards and knife handles,
require only minimal care in order to retain their unmatched beauty, longevity, and practicality.
http://fantes.com/wood-care.html