When cleaning a wooden chopping board, use warm water with a mild detergent and scrub well. 

Use lots of water and scrub the board thoroughly. This will have a bigger impact than your choice of detergent on killing bacteria and removing trapped food particles from the board.

Wipe excessive moisture from the board with a towel and allow it to air dry naturally, away from direct sunlight.

During drying, stand the board on it's end or lie it flat on a raised rack so that as much of the board as possible is exposed.  This will help the board dry evenly and reduce warping.