New Tank Cycling Question

[David]

Hi, I just setup a new 55 gal fish tank and had some questions about getting it setup properly. I had a fish tank about 5-6 years ago and know a little about keeping them and cycling the tank.

First, I would like to know how many fish I should use to cycle the tank. I purchased 4 small goldfish (about 1 1/2 to 2 in. in length each) for a 55 gal tank and 1 of the fish died yesterday. I have had the tank setup for 3 days now and I plan to cycle it for 2-3 weeks or longer if necessary. I have a testing kit so I can test for ammonia, nitrite, and nitrate. I'm wondering if I need more than just the 3 small goldfish in the tank to cycle the tank? I would like to keep more than 3 small fish after the tank is cycled, but I don't want the ammonia and nitrite levels to skyrocket after the tank is cycled because I added too many fish. Does anyone have any suggestions for how many fish I need to properly cycle the tank and how long I should let it cycle?

Also, I purchased 1 live plant for the tank. I have never had live plants so I don't know much about them. Do I need live plants? How many for a 55 gal? What are the pros and cons for keeping live plants?

Also, want scavengers should I add to the tank besides bottom feeding corys or catfish? I saw some snails at the fish store. Do snails work well at keeping the tank cleaner? Should I wait to add bottom feeders and scavengers until after the tank is cycled?

One last question. How often should I do water changes during the cycling process and after the cycling process (for a 55 gal tank). How much water should I change and how often?

Any advice would be greatly appreciated.

Thanks,

David