The silky richness of fine hardwoods in a well made, and cared for, cutting board is a thing of beauty.  Even this humble kitchen tool can be a minor work of art, bringing a little joy to the household chef as he or she goes about their tasks or making a statement during a wine & cheese party.  But like anything worthwhile, it does require periodic maintenance.

Choose your knife carefully.  Avoid any serrated edge knives, especially those wicked "Ginsu" style knives.  Anything that can saw through a tin can will make a splintery mess of your pretty cutting board.  A sharp, smooth edged knife or small cleaver is what you want.

While a cutting board does need to be cleaned after use, you should not soak the board in a sink, or worse - a dishwasher.  Doing so will cause the wood to swell.  Then as it dries out again, it can crack and split.  Instead, sponge off the board with warm soapy water to remove debris and set aside to dry.  If used for cutting meats, especially poultry, you may want to clean it with a kitchen disinfectant, but most other foods won't require this.  Tests run by several labs have shown that natural elements in wooden cutting boards actually combat bacteria, and are less likely to cause food contamination than plastic or polycabonite boards.

Cutting boards use a simple oil finish to protect and beautify the wood.  Occasionally, the board will begin to dry out and require re-oiling.  For this you will need Mineral Oil.  There are several other products available including Butcher Block Oil and Salad Bowl Finish, but these are basically... mineral oil.  Do NOT use vegetable oil on your board.  This would include salad oil, corn oil, olive oil, peanut oil, etc.  These products will penetrate the board and help waterproof it, but will also go rancid with time, causing food poisoning.  Use mineral oil, which is available from many hardware stores and most woodworking stores.  If you can't find these, go to your neighborhood drug store and pick up a bottle of generic baby oil.  This too is mineral oil.  Avoid any brand with added scents or moisturizers.  In this case, the cheapest, most ordinary generic brand will be what you want.

Clean the board and allow to dry thoroughly.  If there are rough spots, sand with 220 grit sand paper to smooth them out, then apply a liberal coat of the mineral oil to one side and the edges.  Allow the wood to drink up as much of the oil as it will, add more if spots dry out, and allow to stand for 5 minutes.  Then wipe off the excess and treat the other side.  There is no "curing" needed, so you can use the board right away if you want.  The oil will bring back the deep luster of the wood as well as protecting it from water damage.

If you are looking for a new cutting board, here are a few tips for selecting a good one.
1) Look for tight grained hardwoods.  Avoid boards made of ANY softwood such as pine, or open grained hardwoods like oak or wenge.
2) Edge grain or end grain cutting surfaces, not face grain.  Face grain is far less resistant to damage from knives, and will not last.
3) Narrow boards or strips laminated together are less likely to warp or split than a cutting board made up of two or three wide planks.
4) Good tight joints.  Gaps or filler in the joints indicate sloppy workmanship, and an inferior product.
5) No dyes or stains.  If you want a cutting board with more pizazz than the common maple board, buy one that uses hardwoods with natural color.  These won't bleed out into your food or interfere with the mineral oil protecting the wood.
6) Do not buy a board that has any kind of a film finish on it.  No matter what it is, it will get cut up and start to flake off into your food.  It may be non-toxic, but anyone who puts a film finish on a cutting board is making a decorative piece, not one intended for use.