I will answer for him - if he doesn't mind.
One Day camps are when colleges have a "Camp" on their campus. It is usually 3.5 hours (no lunch) or 7 hours (lunch provided). Some schools will have 3 or 4 of these throughout the summer. USC Gamecocks are trying a new approach - they are having like 20 One Day Camps this summer. They did it last year and Muschamp said this led to a lot of exposure and opportunities for players. I think I remember him saying that of their 22 signees they saw 20 of them at their One Day Camps.
Clemson does two 3-day camps. Yes, they are crowded, yes a lot of money is made off them, but if your son is on their board, he WILL get 1-on-1 with his position coach. If you are very high on their boards, you will get a 1-on-1 with Coach Swinney himself. Probably even a personal golf cart ride to practice or back to the dorms.
I have looked around, and unfortunately, not a lot of the smaller schools have put up their Summer Camp schedules, yet. Most D-I schools already have theirs up, however, so if you want to take a look at those just google the head coach's name with "football camp" after it and viola, you can find their websites with camps schedules.
Check back in a month for the smaller schools like Coastal, Wofford, Campbell, Western Carolina, etc. They should be putting them up over the next few weeks so people can plan their summers.
Good luck,