I'm certainly not an expert, but this is what we learned.
Probably next summer is most crucial but this summer can help.
Think about what his/your goals are.
Go to The School's Baseball Website to see about camp info. Most list it there.
We liked The TPX event because a lot of the type schools my son was looking at were there. It was a good mix, but if you are thinking big-time (top level D-1) they probably won't be there. Not inexpensive, but local so no travel costs.
The PG Showcase my son went to didn't spend a lot of time looking at the players before making their evaluations, but others have said good things about PG, especially the National Showcases if your son is legitimate Top Prospect. Not cheap.
College camps seemed to be the best, inexpensive and if you want to get your son in front of a Coach that's the way to do it. Some College camps also include coaches from other smaller local colleges. For instance going to The Harvard Camp generated a lot of contacts from schools in the northeast.
If my son were an incoming Jr. and had an idea he wanted to go to a specific school, I'd see if they have a camp and get him there so he can get on their radar. Have him try to contact the coach ahead of time.
Having the people at The PBR get a look at him and like him can't be a bad thing for sure. I'd bet the people connected there would be glad to give recommendations to College Coaches when the time comes.
Like I said, everyone's goals are different, so maybe determining that can help decide which way to go.
Hope I helped.