Super easy to sex them bro, females will have a pink/reddish belly. Kinda in stripes, vertically, just behind the pectoral fin. Males don't have this. Generally the females will be smaller as well. They should be able to start breeding at around 2"...although I've seen them start at 1.5". Once they start though its practically impossible to get them to stop.
Wait for the fry to become free swimmin (two to four days after they hatch), then start puttin crushed flake food into the tank a couple of times a day. The parents will watch over the little ball of babies as they swarm around the tank and eat. Very kewl to watch. Good luck gettin them out. Best way would be to siphone them out, cuz when they see danger they duck into the rocks.