Clean after using to make things easier. Jut use a bit of soap and water. After cleaning, rub down with mineral oil to maintain the wood. If you are going to purchase a wood board, hard-rock maple, end-grain boards are very good, and easier on the knife blade than a board made from side-grain boards.
There is a lot of controversy about whether wood or plastic is more hygenic. Wood has natural anti-bacterial properties while plastic can be scalded in very hot water (the dishwasher). I have been using wood boards for years and have never had a problem. I also use plastic sheets on occasion, when I need multiple cutting surfaces for a meal and don't want to be continually cleaning up the boards between cutting chores. Also, if the veggies are going to be cooked, then I will use the same boards for both meat and veggies, as the steam, or boiling water is well above the temperature required to kill any pathogens. I only worry about cross-contamination when serving uncooked items such as salads, breads, cheeses, etc., where the foods won't be cooked to high enogh temps to kill any nasties. Then I use tnd wood for the veggies, fruits, etc. and the plastic for the meats.
Seeeeeeya; Goodweed of the North