[Harlan Chinn]

Strip any moist wall board to the stud, allow studs to dry. Any moisture will rot your studs. Replace wall board with water resistent wall board if subjected to lots of water. Paint walls using an alkyd enamel or good latex paint. The better paints will allow you to clean and wipe them with out damaging the finish.
Apply a water resistant wainscot of tile or plastic laminate like formica around wet areas (sinks/showers/tubs).
As for flooring finishes, ceramic tiles are of course the better choice but a sheet good is far superior to a tile which will eventually pop off when moisture gets behind it.