First thing, don't underestimate kids' ability to learn new things, it is important to keep them challenged.

I would recommend,

http://www.greenteapress.com/thinkpython/thinkpython.pdf

Python got the turtle, so no need for logo.

Videos makes things easy.

http://showmedo.com/videos/python

Games are also a great motivator.

http://www.pygame.org/

When (s)he gets more advanched, older (think: upgrade path) I would recommend things like,

http://www.sagemath.org/

http://www.scipy.org/

http://www.diveintopython.org/