I've taken Blacksmithing classes at one of our local county parks that has an 1800's Pioneer Village. They have 6 coal fired, hand crank forges, and a couple propane units.
Without question the #1 thing I can't stress enough is safety. You need proper gloves, arm sleeves, leather apron, safety toed boots, and a great first aid kit.
I would also have an emergency contingency plan in place before he even starts. It's not that he can't learn to be a Blacksmith, but he needs to learn and understand the dangers of
what he's getting into. Watching it on TV and dealing with glowing red hot steel are two totally different realities.