Oscars are the typical cichlid substrate spawner.
I have a question for you.... why do you want to know so much about breeding fish?? What are your goals? Because I would think oscars would be the pretty far down the list. A lot of work, and hard to sell. There are just a lot of other cichlids out there that can be spawned and the fry are worth so much more. Oscars just are so common, and so available! If you want to breed some fish and support your hobby, then there are plenty of better choices!