You need to buy a bottle of ammonia solution. Ace Hardware sells it if there's one near you. If not, you could try Ebay/Amazon. If you could find some of Dr Tim's ammonium chloride, that is good too.
Once you get your ammonia look at the calculator section (in How to Tips) as that will tell you amount you need. Then look at Cycling a Tank in the How to Tips for the method.
I should have explained that you need a dechlorinator to remove the chlorine/chloramine in tap water that would otherwise kill the bacteria you want to grow, but any dechlorinator will do that, it doesn't have to be Prime.