Fishless cycle is the way to go. You don't have to do water changes as you would have with a fish in cycle. You don't hurt any fish and you create a big bio load to handle the waste from your future fish. Get everything running (except for lights, they are not needed during fishless cycle). Crank up your heater to around 85 - 88 F and calculate how much ammonia you need for that tank, I have a 120 gal. and it takes about 2 tablespoons to raise ammonia to 5 PPM. You can start adding ammonia in small amounts in 15 minute intervals until your ammonia test reads 5 PPM. The ammonia that many hobbyist have used, including me, is the one from ACE Hardware (10%) Janitorial Strength. Make sure it doesn't foam when you shake the bottle, a few bubbles that quickly disappear are fine. Once you add ammonia, test daily, when you see a drop in ammonia, start testing for nitrites (usually takes about a week). When ammonia drops to 0 PPM, add enough ammonia to raise it to 3 or 4 PPM (when the ammonia you added drops again, add some more to raise it to 3-4 PPM again, eventually, you will have to do this daily as your bacteria will convert ammonia to nitrites in less than 24 hours) and keep watching your nitrites, nitrites take longer than ammonia to drop. This is where you patience is tested. Why it takes twice as long? Simple, because you are adding ammonia as ammonia drops to 0 PPM and because the first step of the nitrogen cycle is where ammonia transform into nitrites, so your nitrites come from the ammonia you add plus the ammonia that was already converted into nitrites, the second reason is because the bacteria that converts nitrites into nitrAtes simply takes longer to develop than the bacteria that converts ammonia into nitrites. This is what happens during the Nitrogen Cycle:
File:Aquarium Nitrogen Cycle.png - Wikipedia, the free encyclopedia. In your case the ammonia source is pure ammonia instead of fish's waste or uneaten food. Once your see a drop in nitrites begin testing for nitrates (they should be way too high). When your ammonia and nitrites finally read 0 PPM both, you are cycled and your nitrates should be of the chart, so it's time for a big partial water change about 80% to drop nitrates. Make sure you add dechlorinator/Prime before you add the new water when doing your partial water change, add enough dechlorinator equivalent to the volume needed for your entire tank, not just for the amount of water you are adding. Ammonia is converted into nitrites, and nitrites into nitrates. Nitrates are non toxic to fish unless in big amounts. That's one of the main reasons why we need water changes, to drop nitrates that build up over time.
If you are not going to add fish immediately after your cycle is completed you can add about 1 PPM of ammonia daily to feed the bacteria, since you will not have an ammonia source until you add your fish and without nothing to eat (ammonia) your bacteria can/will die.
You can also take a look at my topic about "Fishless Cycle"
http://www.aquariumadvice.com/forums/f12/fishless-cycle-147606.html where many of my answers have been kindly answered by other memebers.
