What everyone is saying is wait for the nitrogen cycle(ammonia appears and spikes then decreases, nitrites appear and spikes then decreases, nitrates appear and increase) to finish before adding any fish to the tank at all. It is cruel IMO to add fish to cycle the tank. Germanmann is advising that you wait two more months after the cycle finishes to start adding soft corals because the tank parameters should have stabalized by then.
As far as how long it will take for the cycle to be complete will depend on how much "live" rock you have in the tank. Generally, it takes anywhere from 3-8 weeks. Don't short cut this step though. It is very important to properly establish the cycle to have a good setup in SW.