At what age you will start to teach your kid programming? What language to start with?

Sure, kids love simple programs like: 10 PRINT "Hello" 20 GOTO 10 But do the kid a favour and don't introduce them to programming with C++. Keep it simple, fun, and visual. Not too much theory. I started with BASIC and http://en.wikipedia.org/wiki/Logo_%28programming_language%29. For a more modern language similar to BASIC you could try Python.

Some time ago I read about http://pythonturtle.org/ - "A learning environment for Python suitable for beginners and children, inspired by Logo.". Most children like games and asking them to design their own game would be a good way to teach them programming. Python Turtle seems to do it well.

You can, but still... he needs to know quite a lot of hardware, maths, performance issues to do get programming right. I guess at this age you can just teach him really basis, lik hello world, defining classes, and stuff like this. He might try to create a simple "game" in Console. That would be definitely fun for him. Or a bunch of simple programs (how many days have you lived etc) good luck!

Yeah Like said before, I think the Lego Idea is a good one. For myself, I would say that I loved computers when I was a kid, but programming was something between not human and impossible. And I got the first Lego Mindstorms kit, that was a wonderful introduction the the programming logic. Because you don't have to forget, programming is a state of mind. A programmer doesn't think the same way as a salesperson (for example) So maybe a kid will love it quickly or you can just abandon. But there are some programming languages created for kids... but ... not by kids Hope this helps you ;-)

While some kids grok programming at a young age, studies show that most children would prefer learning through entertainment than for programming's sake. There are many tools and languages tailored for use with children. As a graduated student I worked with some of the people behind http://www.alice.org/. It uses a slightly different approach to teaching programming; it treats programming as a story telling device and children learn programming concepts in the process. The Alice development team was able to work with EA to get many of the models from http://en.wikipedia.org/wiki/The_Sims as "actors" for the application. If you are not familiar with the http://www.youtube.com/watch?v=ji5_MqicxSo, it provides a much better description of the learning process. I have personally used Storytelling Alice in a summer camp setting for middle school children. Depending on the child, you might be able to introduce the concepts at a younger age.

Let your children play! lolol just kidding! In my opinion you should start with something simple... When he's ready (maybe at 13s, it depends) you should try to teach some LISP language (e.g. PLT Scheme).. If he could understand that it will be far easy to understand the other common programming concepts.