Pizza stones help distribute the heat evenly to the pizza or whatever else is in the oven. By its nature, the stone also absorbs moisture for a crisp crust.
Using the stone:
Preferably, set the cold stone in the oven and preheat the oven to your desired setting. Create your pizza on a pizza peel, and when done transfer carefully to the now-hot stone. Alternatively, you can build your pizza on the cold stone, and transfer the whole thing into the oven.
You can prevent sticking by sprinkling some flour or cornmeal on the stone prior to using. Brush off any food residue and you can rinse it in water. NEVER use soap to wash the stone as it may leave a ‘flavor’ in the stone.