With saltwater you have 2 choices just like freshwater:
1: Cycle with no fish
2. Cycle with Fish
There is a million debates out there wich is better, worse, etc. I could care less about either. I have done both and will give you my opinions.
If you want to do it without fish, wait about 3-4 weeks. Maybe within those 3-4 weeks, drop some food into the tank. This will help the process. Also Check your levels and do water changes accordingly. You dont want to do too many, too little. Don't go cheap!!! Get the right test kit, and ROI water now and save the headaches in the long run.
If you want to do it with fish, this is your call. The problem with this is you have to pick a fish you want to stick with. This will have to be a hardy fish, and most people don't tend to like hardy fish. So if you do, maybe you can just buy one, and trade it back to the LFS if you dont want it. If so, wait about a week or so and then add 1 maybe 2 fish. Dont overdue it or your levels will go crazy. Keep the feedings to a minimum, and test the levels often.