If you just want a surface for basic kitchen processing, a no-nonsense countertop board is a great option. As far as the best size, consider what you will be using it for. Food prep, such as vegetable slicing and dicing, only requires a small board, but if you will also be using it for butchery or carving meats, err on the side of more mass rather than less. Wood cutting boards basically come in one of two construction types. End-grain boards (i.e. with exposed grain oriented toward the cutting surface), are easier on a knife edge but can be harder to clean. Edge-grain boards tend to dull knives faster but are easy to clean. The choice is largely a matter of personal preference.