Nothing for you to do now but wait. Once he attend summer seminar, his application will already be started. (The pre-candidate was basically done when he applied for summer seminar). Once summer seminar is over, the academy will open up the website to start the actual academy application.
It's good that you've already made some contact with your MOC. Might be easier to get a nomination when the time comes. Make sure you look at your MOC's website(s). they usually have instructions for how to do "THEIR" nomination process. usually, they ask for transcripts and such AFTER Junior Year is done. So chances are, there's nothing for you to do right now. I would have your son get a hold of his teachers. Get their "PERSONAL" email addresses. In the application process, they are going to have to fill out an online recommendation form. Some teachers are difficult to find once summer vacation starts. In the application, it asks for your teacher's email addresses. If you put the school's email address in there, the teacher may never/rarely check that. But if you put in their gmail, hotmail, yahoo, etc... email account, they are more apt to see it and complete it early.
If you prepare properly, you CAN have the entire application process completed by August. That is what I recommend. Especially if the applicant is physically fit and can pass their CFA and their medical review is good. This opens the applicant up to an LOA or similar. This opens up his/her options when applying for other schools. I.e. My son had his academy application 100% complete on July 19th. Including the CFA, DODMRB, Teacher's recommendations, etc... 100% complete. He also had a presidential nomination, so he received an early appointment at the end of october. Even without a nomination early, it opens him up for an LOA. Plus, my son was able to get all his early apps to 5 other universities all completed by September. This freed up his entire senior year in high school to enjoy himself. Concentrate on football. Date. have fun. Not trying to to do academy and university applications. The only thing he did from 1 Aug on, was to continue taking ACT/SAT tests as many times as he could. Other than that; he enjoyed his senior year. I'm not dogging those who wait until December/January to finish their applications. But it's always better to get it done early. Best of luck. mike....