The biggest two being the order of operations for the program (i.e.: what comes first? Contacting an ALO, doing the application, etc.) and what determines what job you will have as an officer after you graduate?
I am applying to the LEAD program this application season, so my knowledge is limited.
First things first, you submit your PCQ (pre-candidate questionnaire) online. Once your done with the PCQ, then you will be assigned an ALO as a placeholder. You can contact an ALO at any point in the process, but you won't be assigned an official ALO until you make it to the candidate phase. That being said, you are encouraged to reach out to an ALO early on (they have answers to most questions or know where to find them).
Moving on, when the Academy reviews your questionnaire and deems you competitive, you will then move to candidate status where you will start sending all pertinent information: CFA scores, DODMERB, standardize test scores, and transcripts.
At the same time, you should talk your chain of command and relay your interest in the Academy. Your supervisors will be the ones writing your recommendations, and you need you squadron (or higher, i.e. group or wing) commander's nomination/endorsement (hence the AF 1786). I suggest you seek nomination sources outside of your leadership, such as your MOC (house of reps and senate) and VP.