Another that 2 clownfish require an anemone to pair, and without it will just fight. Any experience???
I would ignore any further information from that source. That is pure hooey. All species of clowns can be bred in tanks with nothing more than a flower pot. My ocellaris have never seen a host anemone and spawn every few weeks.
Clowns start out sexless, and differentiate according to their social environment. If they are the dominant clown, or the only one in the tank, they will develop as females, usually within a few months. If they are subordinate, they will become male. If there are more than 2, the remainder will remain undifferentiated.
The usual method of pairing clowns is to either get 2 juveniles, or introduce a small juvenile into a tank with an established female. There is a little sparring, then the smaller fish figures out who's boss and does little seizure like movements to indicate that it is properly submissive. I have not kept maroons, but hear that females can be very aggressive to newly introduced fish. Sometimes they need to be separated, but able to see each other, to become acquainted.
Have a look at this thread if you want to know more.
http://reefcentral.com/forums/showthread.php?threadid=215098
I can also recommend some excellent books if you want to know more.