I probably need to write a blog with full details, but here is a quick overview - if anyone wants to chime in and add details feel free as I don't have a lot of time right now to go into it too deeply:
* The offensive and defensive gameplan screens are the % of uses of each play type/personnel/etc. in each given situation in each quadrant.
* The game engine will choose your offensive play type, then will choose a play based on the weights within that play type. You can see how each play is weighted in each situation via the "View Plays" button. On defense, the personnel will first be matched, then the play type will be driven by the weights for plays that match that personnel.
* You choose your offensive and defensive plays that will be available during the game. Your players will practice those plays during the week and thus will improve their knowledge and ability to perform them.
* You scout your opponent by choosing plays from their playbook to practice against. Again, the more familiar your team is with the opposing team's play, the better they perform.
* "Load Recommended" takes into account your personnel vs. your opponent's personnel. The way I do gameplanning is I start with the recommended values, and then tweak from there, except for one or two elements that I tweak manually.
* In MFN-1, there is a "Rules" section that is in Beta. This allows you to be very specific about play calls in a given situation. This is the first season that this is available so I'm interested to hear feedback about how it works.