We've had our current tank about a year. The year before that we had a grubby one but it was alot bigger. It had a wooden log in the middle of the tank with this bush type thing growing out of it, so when it got too big, we cut it down and sold it back to the shop (because they cant grow it in the shop for some reason). So we pretty much had free fish food and fish replacements.
Heres my current setup:
http://img293.imageshack.us/img293/8541 ... 0342ni.jpg
http://img293.imageshack.us/img293/7735 ... 0358qj.jpg
http://img293.imageshack.us/img293/6991 ... 0365fr.jpg
http://img293.imageshack.us/img293/7220 ... 0371ox.jpg
http://img293.imageshack.us/img293/4223 ... 0385lk.jpg
Always seek advise when buying new fish though, some fish tend not to like certain species of other fish. Usually big and small fish, as the small fish tend to get eaten, Also watch out for the bullys, some fish will take nibbles out of other fish's tails, so watch out for them.
Also cleaning: Make sure its cleaned usually once a week. Try not to leave it much longer than that, as it can be bad on the fish and harder to clean later on. most aquariums are able to test the water for you to make sure it has enough chemicals in the water to keep the fish alive.
You can also treat the fish sometimes with bloodworms. Quite interesting to watch.
Good luck with your tank and fish.