It is not necessary to regularly check power steering fluid unless you suspect there is a leak in the system or you hear an unusual noise. A fluid loss in this system could indicate a problem. Have the system inspected and repaired. See Engine Compartment Overview for reservoir location.
Turn the key off, let the engine compartment cool down, wipe the cap and the top of the reservoir clean, then unscrew the cap and wipe the dipstick with a clean rag. Replace the cap and completely tighten it. Then remove the cap again and look at the fluid level on the dipstick.
When the engine compartment is hot, the level should be at the H (hot) mark. When it's cold, the level should be at the C (cold) mark. If the fluid is at the ADD mark, you should add fluid.
To determine what kind of fluid to use, see Recommended Fluids and Lubricants . Always use the proper fluid. Failure to use the proper fluid can cause leaks and damage hoses and seals.