Research, research, research. My he best way to find out anything about aquarium livestock is to research them on the internet or in books. Don’t go to a store without at least some knowledge about the fish, invertebrate, or corals you intend to purchase. And do not rely on information from the guy selling you these animals. Instead, arm yourself with the right information to make a good decision, and don’t act on impulse. This will ensure that you get animals you are equipped enough to take care of, and nothing you can’t handle.