If they are chrome plated, most any good car wax or paint sealant will work just fine. The best course of action is to clean them frequently and wax as needed. If you neglect them it can be difficult to restore the shine.
Wash with soap, water and a soft mitt or sponge. Stay away from wheel cleaners, rubbing compounds, stuff like steel wool, Scotchbrite pads and harsh chemicals. Polish and wax as needed and they'll look great for many many years.