If you're going to start off with a small tank, the same rules still apply. Allow for the tank to cycle for approximately 2 weeks. What I mean by cycle, is the tank right now is going haywire with the different levels of ammonia, nitrates and nitrites.. Those levels are fish killers. To help move your tank forward a bit faster to cycle the tank, add live bacteria and/or live plants. You're going to want to add fish last. Test your water throughout the two weeks. There are going to be days that the nitrites are higher then the nitrates and vise versa..
Once the tank has calmed down a bit, you can start to add your fish. You're going to what to start off with the hardy fish such as Zebra danios. They're very hardy fish and can handle just about anything. I'm not quite sure what fish you're interested in adding, if you want to stick with the tiny schooling fish or if you want to do something else..
Dont ever add all the fish you want at one time. The tank goes into shock and the fish are killed instantly. Add two or three at a time over a month span if not longer. Once again, start with the hardy fish first. Your pet store who you're buying fish from can help you out on that.
Also.. Don't over populate your tank. Believe it or not, but the smaller a tank is, the harder they are to keep clean. The rule of thumb is 1 gal per 1 inch of fish.
Also, another good thing to help with your tank and making it healthy, add salt. Salt that is purchased for a freshwater aquarium adds electorlites to the water making it a healthy and stress relieving environment for the fish. Directions are on the back of the box. Adding salt also helps with disease.
If your going to be doing tropical fish, keep the water between 75-80 degrees. Some fish like it warmer.
A really good water conditioner that I would recommend would be the PRIME by Seachem.. Its a red bottle. Prime has a lot of good things in it. It has live bacteria that help out with the new tanks cycle. It also helps in maintaining healthy levels of ammonia, nitrites and nitrates.. Which should always test zero.
Marineland biowheels are very good filters. The wheel itself is going to grow good bacteria that the tank needs. You will never need to clean. It should always remain kind of dingy.
Also.. Once the tank cycles for a good month, you're going to want to start the water changes. There should be a 25% water change once a week and 50% water change once a month. Like I said, smaller tanks are harder to keep clean, so really make it a habit to get those water changes done each week! Never EVER empty the tank out completely and scrub it clean. You want to keep the good bacteria in your tank. Removing the rock and rinsing everything clean kills it off and when you put everything back together, the tank cycles all over again. Whenever the good bacteria dies, your fish die.
Also, don't worry about purchasing any type of algea eater until you see algea on your tank walls or decorations. Algea is ugly, but once algea starts to grow, that mean you have a healthy tank!
If you have any more questions just ask.. I think I covered most of the basics!