Cleaning it as necessary is one part of the way. The other is to apply a protective coat of wax. We recommend GelGloss. It is like a furniture polish that should be applied every few months, depending on use. Boat wax for fiberglass boats is also a good means of protection.
Cultured marble is very rugged with a hard waterproof, stain proof surface.
If it should scratch or chip, repairs can be made by shops that make cultured marble. Sometimes all that is needed is sanding and polishing. Other times the chip must be filled with the same cultured marble it was originally made with. Both of these procedures require a person with the knowledge and tools. The better marble shops have their products tested once a year by a testing laboratory for compliance with ANSI specifications.