Hope this helps you to get a good understanding of aquarium keeping by keeping this as simple as possible while still providing the necessary information you NEED to be successful in this hobby.
1. Decide which fish you want to have.
2. Find out what size tank will house your
fish comfortably and then buy one at
least 10% bigger.
3. If you buy as a package, make sure the filter will turn over the volume of water at least 3 times per hour. So a 20 gallon tank needs a filter rated at 60 gallons per hour minimum. If you intend to have plants make sure the lighting supplied will be suitable to promote plant growth.
4. Okay, so now you have a tank, stand, light and filter and getting really excited about setting all of this up. STOP!
4a. Choose a location for the tank with consideration for windows, viewing and maintenance required such as water changes etc. Moving tanks once they are set up is not easy.
4b. Spend a little time to decide on the substrate for the tank especially if you intend to have plants then get the substrate to give you the depth required.
4c. Decide if and what types of scaping you would like such as rocks, driftwood etc and buy/ acquire them.
5. Finally!!!!!! Place the tank in the desired location, rinse the substrate as required to get rid of the superfine particles and dust and place it in the tank. Sculpt to suit your taste.
6. Thoroughly wash any rocks, driftwood etc and place as desired.
7. Woohoo!!!!!!! Water! STOP!!!!
7a PLEASE get a master test kit ( not strips) and follow the instructions carefully including on how long to shake things. Test the tap water and record the results for future reference.
7b Fill the tank.
8. We now have a fairly sterile tankfull of water with probably some chlorine and chloramine and other stuff and may be a bit cloudy. This will NOT support any fish at this stage. Add some water conditioner to get rid of chlorine and chloramine and bind any heavy metals e.g. API, Seachem etc.
9. Assemble the filter by following the instructions or if no instructions ASK!!!!!
and turn it on. Now we have a tank with water that is filtering. No need for the lighting at the moment.
10. Add fish??? NOOOOOO!!!!!!
10a If you don't know about the nitrogen cycle please do a search and aquaint yourself with it. THIS IS THE MOST IMPORTANT STEP IF YOU WANT TO BE SUCCESSFUL!
10b Ensure that the tank is cycled by either fishless or fish in methods and keep testing regularly to confirm that the tank is cycled. That's what the test kit is for.
Finally we can add plants and fish with a pretty good chance that we are not going to kill everything.
All of the terms I have used can easily be found on this site together with cycling instructions and if anything else is unclear just ask and a lot of members will only be too happy to help.
Aquarium Nitrogen Cycle