[jberryman]

Get him legos, things he can build with his hands, internalize the process of building, designing, visualizing. Do lots of projects with him. Show him how stuff works. Give him musical instruments to play with and give him lessons.

Honestly programming isn't that hard. If he finds it interesting he can start teaching himself at any age, so I wouldn't focus on that. All that said, IANAD. congrats on being a dad!