What sort of stuff do you want to know?
They live happily in almost any type of water, hard or soft, ph anywhere between 6 and 7.5, possibly more.
The size of your tank will determine the number of females you can get. Each female will require roughly one square foot of territory, and one or two caves per female.
They will spawn. This is almost guaranteed unless you are keeping them in bleach. As often as two weeks apart under the right conditions. The female will become quite agressive, and probably finish off those tropical goldfish of yours unless there is sufficient space, as goldfish are quite slow moving.
My first spawn was around 50 fry, so be prepared for an awful lot of babies. They will attack fish much bigger than themselves when defending fry. It is not unheard of for the female to have two or more batches of fry at different ages, or for the father to take over care, when the second spawn happens. The father is unlikely to eat any of the fry, but it does occasionally happen. Your other fish would be more of a worry.
Also, your catfish will probably be a very good population control.
Temp should be around 26 degrees c, to 28 degrees c.
Very little water movement, and lots of plants and caves and cover, flower pots, coconut shells, bogwood, that sort of thing. Floor space is more important than depth.
Live foods are important, although flake will be ok (Bit like the way a person could survive on ready meals, but fresh food is good.) . Frozen foods are also good. Things like brine shrimp, and bloodworm. If you intend to keep and raise the fry, you will need to learn to hatch baby brine shrimp.
Males can get to about 3.5 inches (8-9 cm or so), whilst females can get to around 2 inches (5 cm ish). They often stay much smaller than this though.
They are a marvelous fish to keep, and they will learn to recognise you in a very short space of time, and will always be happy to see you. Esp if you have food
It is so magical when the female starts bringing her fry out to show you, as she becomes quite proud.
If you wish to be a little more specific, I'm sure I can answer most questions
Ian.