Here are the basic 15 easy steps to set up a small aquarium; this is the way I did it, when I set up my first Tropical aquarium some years ago.
1>. You need a 12x12x24 Aquarium with a hood.
2>. You need to buy some books about fishes and aquatic plants.
3>. Lighting you need 1x T8 lighting unit with plant growth T8 bulb and 1x T8 lighting unit with a Moonlight T8 Bulb 16watt each.
4>. You need a 300-400 litres per hour flow filter pump and a good air pump with a air stone.
5>. You need a 50-100watt heater and 6-8kg of natural aquarium gravel.
6>. Stand your aquarium somewhere shaded (Not in direct sun light) as this will make the Algae grow faster and make the glass go green and make it hard to clean.
7>. Once you placed you Aquarium where it looks good, now place the washed gravel into the Aquarium and place a old plate upside down on to the gravel and now slowly poor treated water on to the plate, and then fill the aquarium up to about one to two inches near the top then take out the plate. Remember that an Aquarium is very heavy when water is in it so make sure that where you place it can hold the weight of the aquarium or if you are placing on something like cabinet, table ect.
8>. Now place the heater into the Aquarium and make sure it can not move and the you can put in the filter pump and the air stone into the aquarium. Make sure that the air pump is away from the aquarium so water can get into the air pump, if you are going to put rocks into the aquarium never put them next to the heater or they might damage it or near the glass to, make sure that the rocks don't move at all.
9>. Now before you turn on the power, you can plant your aquarium with aquatic plants to make it nice for the fishes and also make the aquarium nice to look at.
10>. Add good bacteria to the aquarium and switch the power on and put the timer for your lights setting the daytime light for 10-12 hours and nighttime light for 6-7 hours, and then leave the aquarium alone for up to 4 to 6 weeks. This gives the good bacteria time to make the aquarium safe for fishes to go into the water.
11>. Get you self a good water testing kit and treatments for you new aquarium.
12>. The most important treatments is tap conditioner and filter bacteria.
13> After you waited for 4-6 weeks it time to put you first fishes into the aquarium, always buy 4-5 fishes every two week so this give time for your filter to adjust to the new fishes.
14>. You must give the aquarium a water change every two weeks, when you change the water you must switch off the power before changing the water or putting your hands into the aquarium, and then take out at lest 1/4 of the tank water and replace it with treated freshwater, and then clean out the filter pump by using the old tank water to the water goes from dirty to nearly clean (Never use tape water to do this, use the tank water to clean out the filer sponge).
15>. Sit back and enjoy your new hobby as the fishes swim around in their new home.