There are a couple of ways to do a fishless cycle, this is a good one:
You need bottled ammonia. It can be found in grocery stores, maybe hardware stores if you can't find it there. Make sure it does not contain any soaps or perfumes. (if it is colored or foams when you shake it, don't buy it)
Make sure all your equipment is running for movement and oxygenation. Heat the tank up to the high 80's, this will help speed up the cycle.
Carefully add ammonia to the tank a bit at a time, testing after each addition, and keeping track of how much you are using. When ammonia in the tank measures 4 ppm, stop adding and note how much it took to get there.
Add this amount everyday. Eventually you will see the ammonia begin to fall and the nitrite begin to rise. At this point decrease the ammount of ammonia you are using by half. Keep adding daily, and testing. When nitrite and ammonia are both 0, you are ready for fish.
Keep adding the ammonia every day until the very day that you add fish. Do a 75-100% water change before adding them, this will take care of the nitrates that have built up from the cycle, and also make sure no un-converted ammonia is in the water. Make sure the heat is at a normal level as well.
To further speed up the cycle, add media from an established filter to your own filter. Obtain this froma friend or the LFS. This will introduce the bacteria direcly into your tank, giving the cycle a very healthy boosts - cycles have taken as little as a week with this method.
Hope this helps