I would introduce him to coding by starting with the basics of HTML and progress through the following:

(install MAMP or WAMP for him to get him started, then get him a domain name and hosting for his own simple website)

HTML CSS javascript jQuery PHP MySQL

I recommend Head First HTML and CSS to get started. The other books in the series are good as well all the way up to Head First PHP and MySQL.

TeamTreehouse.com is a good place to start as well or pick up with once you make it through a few of these books.

Once he gets through those I would point him to learning Rails and/or Laravel frameworks creating a few web applications.

Apps are fun too if he has an iPad and/or iPhone go through the iOS App tutorials on TeamTreehouse.

Good luck in 2015.