It really depends on what you get. For the most part though people wedge, place, glue, or tie corals into place. Within a few days, they will attatch to the rock. Most SPS corals need to be glued or wedged. Also if you get an anemone, dont do anything to it, he will move on its own, and will pick a spot it likes. If you do a search on the subject you will find a little more info.