After thinking about getting my son thinking about doing more with a PC than just playing games I thought a mirco controller might be a good gift for his next birthday. His logic is quite sound so I think, with some help, he'll be able to program up some simple processes. I'd be keen to know which board would be best suited to him for initial I/O programming eg traffic lights through to more advanced things when he builds his experiance.
Thanks in advance,
Michael.
The standard duemilanove is what I started with when I was 12. I still haven't found a situation where I needed any more processing power.
Get the Uno board, it's the modern equivalent of the duemilanove.
Also check this beginnersguide - Loading... - It is based upon a starterskit but the PDF is free for non-comercial use . It has an intro and several projects. The author is on the forum too, see - http://arduino.cc/forum/index.php/topic,70320.0.html -
Thanks so much for the replies.
I have never damaged an arduino board due to misuse. But it definitely is easy to do, if one is not careful.
So either make sure he knows to be careful and to avoid simple mistakes, such as shorting 5v to GND, or spring for the ruggeduino as mentioned by codingbadly.
Thanks for this info CB. This is just the thing I was looking for and it's all very helpful to get the 12yo started without stressing out too much that he'll let the magic smoke out. 
The other thing that's very appealing with this is the (this) community and open source not to mention the cost. 99.9% of the post are very encouraging with all the people out there willing to provide valuable input into designs and code reviews.
I'm hoping my son will find this interesting and challenging and that he'll also be keen to share his progress with you all.