[fatso784]

This might sound totally narcissistic but here's how I learned programming: Taught to play Chess at an early age; Taught another language (Russian, even though I never finished) at an early age (note that I didn't really like learning Russian, but it helped regardless); Given Legos and Lincoln Logs. Basically, any toy that uses building blocks encourages the kind of thinking used in programming; Read to often (but not about programming); Taught BASIC (the concept of "goto" goes a long way in realizing what is possible.); Got into creating game mods (as previous user recommended)

My parents actually sort of discouraged me from liking programming. If I would have, say, been really interested in chemistry and experimented with chemicals, they would have been less worried than when I would work on the computer for long periods of time.

It's also worthy to note that your son may not be interested in becoming a programmer, so don't try to consciously influence him. Surround him with the tools he needs. He'll find a way from there.