Wow, you guys are great. I'll try to answer/comment all your questions: I have some experience bird hunting, upland and duck with an out of state friend, and rabbits with my grandfather 35 years ago. My son has none but is very eager to learn.
As for familiarity with guns, my son, having just started trap and skeet shooting with me, does quite well with his vintage Model 12 (high teens trap, low teens skeet). We are very comfortable around guns and are very safety conscious. My son has never shot a large bore rifle, but is competant with a .22. To answer the why rifles question: we happen to have 2 suitable rifles (a .270 Winchester and an 8mm) but only 1 suitable shotgun (the Model 12). I have one other shotgun, an O/U Beretta which might be good for turkey but I don't think it's appropriate for deer. It would not be a problem to buy another shotgun.
We will definitely be checking out videos.
Thanks for your help so far.
Peter