Locate the power-steering reservoir under the hood of your car. It will be connected to the power-steering pump and a pulley, as shown below:

Printed on the side of the reservoir is "upper level" and "lower level," shown below. You never want to go under the lower level or you'll burn out your pump. If you go over the upper level, the fluid could overflow and spill onto the engine; when the engine heats up or the alternator sparks, the excess fluid could cause a fire.

Open the top of the reservoir to see where your fluid level reaches, making sure not to allow any debris inside the reservoir. If your reservoir is clear enough to see the fluid inside, you can just look to see the fluid level without opening the reservoir.http://news.carjunky.com/car_maintenance/how-to-check-power-steering-fluid-cdh085.shtml 

Once you've determined that you need to add more fluid, make sure you purchase the correct type of power-steering fluid by referring to your car's Owner's Manual. You can use a funnel to add the appropriate amount between the lower level line and the upper level. If you use too much, remove the excess fluid with a syringe or turkey baster.

Replace the cap, and you're ready to roll!http://news.carjunky.com/car_maintenance/how-to-check-power-steering-fluid-cdh085.shtml