Welcome to HSBW! You will find that this site provides an enormous amount of extremely helpful information.
FWIW, I think a summer team is very important. Once he hooks up with a summer team, he should send email of interest with a schedule to schools he is interested in. Perhaps even some phone calls.
On top of that, if my son was in your son's situation, we would also target a few showcases where schools of interest will be. Have your son let them know ahead of time that he is coming, anxious to meet the coach, etc.
It is certainly not too late. My son's summer organization's 18u team had 19 players commit in the summer after graduation. So, if your son is aggressive, and has the talent, he could sign somewhere.
Best of luck to him and keep us updated.