Are they not printed on adhesive vinyl? If they are, then you just peel off the protective backing and stick it down. If not, then get 3M adhesive vinyl from Home Depot.
Here is the tip of the day(if it is adhesive vinyl) - spray a fine mist of water on your CP before putting down the adhesive vinyl. This will keep it from sticking hard right away and allow you to move it a little bit once it's down. Once you get it positioned just right, use a roller to roll out the moisture. Wipe the whole thing off with a paper towel and you get a perfect application.