Lucas writes (excerpted):

When I try to open IDLE as instructed on page 11 I get an error message.

Error dialog

Any suggestions?

It depends on which version of Python you're running, but if you've installed the latest (3.4.2), then instead of putting the following in Automator:

open -a "/Applications/Python 3.4/IDLE.app" --args -n

Try putting this instead:

/Library/Frameworks/Python.framework/Versions/3.4/bin/idle3.4 -n

The reason the text in the book doesn't work is a difference between Automator in versions of OS X prior to 10.7 (I believe 10.7, anyway) and later versions of the operating system.