We always line our cookie sheets with a piece of parchment paper, it keeps the cookie from sticking to the sheet and from over-browning. You can find parchment paper either in rolls or in pre-cut sheets in most grocery stores, and we highly recommend it. Ideally, you should use at least 2 cookie sheets when baking cookies. You don’t want to add the raw cookie dough to a cookie sheet that is hot out of the oven. The dough will start baking even before you get it in the oven.