Only one I could find that talks about post snap
It is hard for me to explain on a message board how to read coverages post snap because for guys like me that have been doing it for so long it kind of comes naturally.
The easiest example I can give is one that happens frequently in Madden. Presnap the defense gives you a 2 deep press look. Using the coach stick your X receiver has an advantage in speed and release. He is running a go route, but because it is a 2 deep look that is not your primary target. (For now I'll simplify it and say the X receiver lines up on the same side as the TE. That is not necessarily correct but it works for now)
I snap the ball and because my first read is always the middle, i.e. the inside LBs and safeties, I immediately see the SS come down and the FS drop back to deep center. Without making anymore reads I immediately throw the deep ball to the X receiver even though I just said he is not my primary target. (before throwing I will "peek" to make sure he got off the line cleanly).
Because that SS came down and the corner was in press alignment I knew I had my shot, because there is no one on that deep part of the field. I don't care if it is cover 1 press, or cover 3 press. Makes no difference. I don't make that pass if that SS drops deep though.
Like I said, that is the easiest example, but it illustrates the point -- all you do when you read the coverage post snap is see where the defenders are going. Thats it, don't get hung up on trying to identify the whole play.