Another good book for teaching Python to young people is "Hello, World" by Warren Sande and his 10-year-old son, Carter:

http://www.amazon.com/Hello-World-Computer-Programming-Begin...

Scott Hanselman interviewed the two on his podcast back in January:

http://www.hanselminutes.com/default.aspx?showID=212

It was a good program.

And it's free online which is pretty cool.