If you don't have any floor rugs in the kitchen, daily mopping and vacuuming just like other floor materials should maintain longevity of the hardwood.

Use floor mats at entry ways to help eliminate sand and grit that can damage your wood and use water sparingly. I like the hardwood floor cleaning products by Bona. They are biodegradable and don't leave a dull residue like some detergent based cleaners.