I am something of a pizza fanatic, eating it at least once a week, and to get pizza at home that can get anywhere close to rivaling those baked in lovely wood-fired ovens, you'll need one of these. The stone serves as a porous, pre-heated surface that aids the crust by removing moisture and distributing heat evenly across the base. Homemade, store-bought, or even reheated delivery will never be better than when cooked on a pizza stone.
Most commercial stones come with instructions for use, but there are also several online resources to answer any questions as to their proper use and how to achieve the best results. If you don't want to spend the extra money for a name-brand, you can head to your local hardware store and pickup an unglazed terra cotta tile that will do the job perfectly. Just be sure to get unglazed, the glaze is usually made with lead and that is not an appetizing topping.
For homemade use, I dust the stone with a bit of cornmeal, then place in a cold oven, pre-heat to 500 F, and let the stone sit in the 500 F oven for about 30 minutes before cooking. Pop the pie on the stone and cook until the crust/cheese are golden brown. Simple as that.
With results like this, who can argue?
A peel is a great tool for moving delicately constructed pizzas onto the screaming hot stone with minimal difficulty.
Here's another post with my basic pizza dough recipe (I usually alter this recipe to 16 oz. AP flour and 4 oz. Semolina flour for my pizza dough.)