lubrication

I have numerous gate valves in my home. For example, the water cut-offs for outdoors, and even the master water cut-off are all gate valves. Am I supposed to be doing something to properly maintain or lubricate those valves? Should I put WD40 on the stem, or perhaps spreading on some plumbing...

I sprayed all the assorted hot and cold water valves in my basement's metal pipes with WD-40, not realizing WD stands for water displacement and that may not be the best thing to use, since it does not leave a lasting lubrication on the valve seals. My intention is to just keep the valves in tip...