If you have two and one is larger than the other the bigger one is most likely a female.
If they are both the same size wait it will happen (kind of like build it, they will come

).
As one becomes more dominate it will grow and change into a female.
As far as pairing thats best left up to the clown fish! All we can do is try and point them in
the right direction, buy doing things like putting them in the same tank. leaving them
alone in the same tank (no tank mates). once again. wait and it will most likely happen.
If you want more information go to the
Marine Ornamental Fish & Invertebrate Breeders or
MOFIB site. There is alot of information on this site,