Well, I have decided to take up yet another hobby and start myself up a small tropical freshwater aquarium. It will be my first time keeping tropical fish, and I've done the right thing and not jumped right into everything. I have been doing research for several months online (as well as at the library) on the basics of keeping tropical fish, so I'm familiar with the seemingly endless options available to me. However, I would like to get some opinions directly from those who have experience. Here's my situation:

I have a 15 gallon tank that housed 2 goldfish happily for 9 years (and to think, I won them at a carnival). They were completely disease free (at least from what I could tell), and I enjoyed them a lot...except for the almost daily cleanings. I live in the country, so I used regular tap water for them (the water is from a well, thus it is not treated with chemicals). My last goldfish passed on in May of this year, and the tank has been sitting empty ever since. I am wanting to use this 15 gallon tank for my future tropical freshwater set up, but I'm wondering if it would be safe. I know that goldfish produce A LOT of waste, thus resulting in insanely high ammonia levels. Would this effect my tropical setup even if the tank has been empty for several months?

Also, since I have not purchased any fish, I would like some suggestions as to what kind of community I should establish. I enjoy the looks of the Bettas as well the Fancy Guppies. I also read somewhere that a dwarf cichlid tank would be very colorful as well. I would like to have some specific suggestions on what YOU would put in my 15 gallon aquarium.

Any advice would be greatly appreciated!