I think you're proposing to start at the wrong end. It is far easier to use Puppet effectively when you understand the basics of its mode of operation and have an idea of the nature and scope of the things it can help you do. To that end, I recommend reading the official architecture overview and the language reference sections of
the Puppet reference manual. Don't let "language reference" scare you: Puppet's official docs are a pretty easy read. I generally recommend also that people at least skim the resource type reference, to get an idea of the kinds of resources Puppet can handle straight out of the box.
You could also consider grabbing
the VM-based tutorial (which I recommend for
after the above resources, but YMMV).
Once you have a foundational understanding of how Puppet works, you will be better able to judge what other resources you want or need to seek out.
Good luck,
John