Ya, fish-less cycles are most recommended now. You can use the shrimp technique (probably the hardest to mess up), but it starts to smell and will require lots of water changing. Basically you just drop a couple cocktail shrimp in the tank and monitor your ammonia, nitrite and nitrate with the test kit. The shrimp supply the bacteria and ammonia. Never overlook a proper cycle, it is very important to the short and long term health of your fish. I have been cycling tanks for 12 years, and some times it takes a week and some times it take three weeks. Brackish seems to take a bit longer (I'm currently cycling a brackish tank and its taking a long time), so your probably best to cycle the tank fresh water and slowly (less than 1.002 SG per week) raise the SG to 1.005-1.007. I wouldn't hurt to buy some of that bio bacteria supplement at a pet store. Gives you a kick start with bacteria. SOme will disagree with me here, but i have had lots of luck with bio supplement and it seems to speed up the cycle.
Filter needs to be on as that is where most of your beneficial bacteria will colonize. They need disolved oxygen and a tank with no current = low oxygen.