Am I right in thinking this may be good prep for migrating to linux?

Yes. And the shells (the command-line program: normally cmd.exe on Windows and something like bash or zsh on Unix) on Linux/OS X/Unix are much much more powerful, so it's even better.

(The Unix shells are actually (Turing-)complete programming languages and non-trivial programs can be implemented in them. Although this isn't a good idea normally.)

(Edit: it seems that that book teaches you to use Powershell, which is similar to the Unix shells (i.e. it doesn't suck), so this comment is probably irrelevant.)