Saltwater Aquariums for Dummies. And there are a bunch of things on line. Just google something like "setting up saltwater aquarium". I have a 29 gal
Biocube by Oceanic, might be a good choice as it is an all in one tank. Just need to add a heater. There are other all in ones like JBJ, solana, etc. just look up nano tanks or all in one tanks. ONLY use saltwater from your lfs
(local fish store) or get a reverse osmosis/ deionization(ro
) unit to make your own at home. Never use tap. Get a master test kit to test your water. A good one too. Not the test strips. There is way too much to go on about. But I feel these are a couple of the musts for starting a saltwater tank. The heater for the tank is a must have. Just read and read and get information from different sources. Dont trust your Lfs
unless you know them well. Not saying they are all no good, but they are there to make money and some just don't have the most knowledgeable staff. Good luck.