You must exchange your license from your prior state within 30 days of moving here and now becoming a resident of our state of New York.
Does that thirty day rule still apply if I have moved here from a province of Canada?
It does.
What is the procedure for the exchange of licenses at the DMV?
You will need to pass a vision test or bring a completed Eye Test Report with you.  You will then surrender your old license along with providing proof of identity.
Will my adult son also need a New York state drivers license if he is only coming here to study at the university?
Is he going to be considered a resident of New York state or is he going to maintain an address of residence elsewhere?
He is not going to claim residency in the state.  His residency will remain in Canada between semesters and after completion of schooling.
Does he possess a Canadian drivers license that is current?