Besides the tank, you'll need:
-a good hang on back filter (this will provide filtration and aeration for the tank - you won't need an air pump or air stone if you have a good hang on back filter - unless you want bubbles for decor) You need to have disturbance at the surface of the water for oxygen exchange to take place (so the fish can breathe)
-a heater
-Gravel - If you want to put fish in right away, rinse the gravel that you buy (with plain cold water) and put it in the tank.
Then cut the toe off a stocking and put in 1 or 2 cups of gravel from a tank that has been up and running for a long time. Your local pet store will probably give you some if you ask. Gravel from an established tank will have the bacteria your new tank will need to jump start your biological filter. Then you tie a knot in the stocking and drop it in the tank.
-a lid.
-a net.
-and a gravel vacuum and bucket for tank changes
Also, not totally necessary but something I recommend, a bottle of Cycle. It's called, "Cycle" you can buy it at your pet store, it helps your fish with stress and has live bacteria in it as well.
And that should have you running.
