See Engine Compartment Overview for reservoir location.
The power steering fluid does not need to be checked regularly, unless there is a suspected leak or an unusual noise. If there is fluid loss, have the system inspected and repaired.
To check the power steering fluid:
The level should be between the COLD and HOT marks. If necessary, add only enough fluid to bring the level up to the COLD mark.
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.