I do think playing Rugby with a club is very good for boys. A group of them put together from many different schools and backgrounds. They have to work as a team, take direction from strong male role models.. and they actually have to learn not to REALLY hurt each other.
Sorry, don't mean to butt in but anything with rugby in the title tends to grab my attention
I would concur that club rugby is the best bet and would add that in my opinion part of the joy of it is that my DS's meet boys from all different schools. It widens their social network and is a great way of meeting other boys they wouldn't normally come into contact with purely because of time restraints and being at different schools. My other tip is to buy yourself some top quality thermal underwear