Some people feed once a day some four times a day. Some only feed every other day. The only thing to remember is to not overfeed. You fish should be able to eat all the food in a few minutes without much of it hitting the ground (unless you intend for it to in the case of corys etc.) I feed my fish once a day, this is my preference. There are a lot soft leaf plants in my tank so if they need a snack they just munch on some of those.
When I had convicts I fed them freezed dried bloodworms and they loved them. You will find though that convicts will eat just about anything you put in the tank!!!