if you only want to keep fish, then you dont need anything special for lights. its good to have live rock and live sand, because it helps with your filtration. a lot of people run regular hang on the back filters on tanks around or under 75 gallons. a protein skimmer is good to have for good water quality, but its not necessary. and you should have atleast one or two powerheads, to keep water moving around the tank. dont make your sand bed too big, under 4 inches or even smaller. having a bare bottom tank is another idea, it helps keep your tank clean. just an idea.