http://hometown.aol.com/kmam1/MyPond/Sex.htmlthis link is available over in the Goldfish Breeding link to the left. It's a very good section to look through.
Now though, if your fish just died, I'd be a bit reticent about getting two new fish to breed. Breeding can be expensive, and it's very very time consuming.
Before you even consider breeding, you need to be able to keep one fish alive.
You have a 5.5 gallon tank. This is not even big enough for
one fish. If you want two fish you need to buy a 20 gallon tank. Then get a filter designed for that gallonage or higher, which is better. You need an air pump and stone. Then you also need to buy test kits for PH, Ammonia and NitrItes. You'll also need water conditioner to remove chlorine from the tap water.
You need to let this tank cycle for a week or more, then add your first fish. Check water parameters daily and do 25% water changes when the ammonia and nitrites start to rise. One the parameters have settled back to 0 then you can add the second fish. Watch the water levels again, but they shouldn't fluctuate too much.
Then you will be doing weekly water changes, and equally checking the water quality a couple times a week.
This is just to take care of them. Breeding is a *whole* other story.