Depending on the age, dedication and fitness levels of your son...
(Consider the following just a rough guide)
Bait
Pro: Low effort, multiple bears, easy packet, lower cost
Con: Not overly valuable to applying lessons learned to other hunting methods and targets, see same handful (relative) of bears over and over, same minimal view(s) every single day
Spot and Stalk
Pro: Learning applies to all type of hunts and targets (glassing, tracking, general Q/A with guide), see lots of country, potential to see new bears
Con: Higher equipment costs, potential for fewer bears, potential for extreme physical exertion, potential for major pack out, higher cost
Hounds
Pro: Increase odds of finding bears, ability to pass on bears, high excitement, general Q/A with guide, see lots of country
Con: Potentially for extreme physical exertion, may include riding horses/mules in nasty country, even higher cost
Ideally you'd get a mix of hounds in the AM and spot/stalk in the PM. Can learn a ton about glassing, tracking, food sources and general availability throughout the year, other animals, field judging, etc.