The best protector for wood is a clear sealer. Many people like to varnish their wood. This looks very good, but it requires a lot of maintenance. Make sure that the sealer you buy is one made specifically for cedar with ultraviolet (UV) reflectors. Whether you buy an oil-based or water-based sealer is unimportant. When you start the job, make sure that the surface is clean and dry. Sand the wood lightly before applying the sealer. You will have to add a coat of sealer periodically, but the process will require little preparation. People often apply too many coats to the wood. One or two coats is enough.