The search tool is very handy. I'll cut you some slack and answer your question.
Oscars are immaterial which means you cannot tell male from female when you look at them. The best way to get a pair is to buy 6 oscars under 4" and place them in a tank at LEAST 125G long. When they hit maturity, you should notice 2 oscars always hanging together and possibly driving the other fish away from thier section of the tank. 9 times out of 10, this is your pair. After you've figured out the pair, sell the other 4 oscars off for a bit of hobby cash.
The oscar pair may not produce a viable spawn for a while, but the more they breed together, the more they learn on how to do it. Never remove the eggs.