Buying a Tank
First you need to decide on a size for your tank. Most pet stores sell starter kits and these are very highly recommened for beginners. Some recommend a big tank for beginners for the following reason; larger tanks are easier to take care of. Basically, the bigger the tank, the longer and harder it is to get dirty. Smaller tanks and bowls require more time and effort to keep clean and fish friendly. When purchasing a tank, try to keep in mind what species of fish you are planning on keeping. Different species require different size areas to swim in. Just because a fish is small, doesn't mean it won't need a lot of room to swim about. Also, make sure you also purchase a cover or hood for your tank, to keep cats and children out, and to keep your fish in!
Once you have purchased your tank make sure to wash it out before you fill it. Hot water and a cloth should be all you need. Never use any kind of detergent or soap in your tank.
Next set the tank up where you want it. Make sure you like where you put it because it gets very heavy when it's full! Put in gravel and any decorations you have before adding water. I also recommend washing both to rinse any dust or dirt off them.
Lighting
If you are planning on having live plants in your aquarium, make sure you have the right light to help it grow and survive. Most pet stores will have special lighting fixtures for aquariums that will vary on the size of your tank.
Heater
If you are going to be keeping tropical freshwater fish, you will need a heater. Again, there will be different varieties of heaters for tanks depending on size and your personal preference. I recommend an automatic heater with a built in thermostat that will turn the heater on and off in response to the change in the water temperature. You will also need a thermometer to check that the heater is functioning properly, and that the water is at the correct temperature for your fish
Filter
Almost all fish will require a filter, especially if you have a large tank. Filters help to keep your water, gravel and plants clean as well as keeping the water safe for the fish. There are many different types of filters you can buy, but I won't get into that here. When buying a filter look for an easy to use, quiet and effective brand. Ask around at pet stores or if you have friends with fish tanks to find out what type they use. Follow the intstructions on how to set up your filter and maintain it.
Water
Now comes the water! Bring the water level up to within 1 inch of the top of the tank. Make sure to add a chlorine remover to the water, and any other conditioning products you have chosen. Some aquariusts test their water for Ph and water hardness and other things. I personally don't, I use a cholrine remover when I do water changes and make sure to change my filter cartridge regularly. You can purchase water test from most pet stores to check the quality of your water.
Setup
Plug in your filter, and if you have a heater make sure the water isn't too cold, before you turn it on, or your glass will crack.
Everyone has a different opinion on how long you should let your tank cycle before you add fish. Some say a week, three days, etc.... I personally let both my tanks cycle for about 24 hours before adding my fish. Also the larger the tank the longer you should let it cycle.
Choosing Fish
Now the fun part, picking out your fish. All I can say here is do a little research before you buy any fish! Make sure that all your fish will get along or you will have problems from the start.
Refer to my Fish Profiles and Fish Tips page for more information about buying fish for your tank.