I've only done a very limited amount of perl::Tk stuff, but for what I did, I found that the documentation was helpful enough... it doesn't necessarily make things easy, but it at least gave me enough direction so that I figured things out eventually.
I would start with the UserGuide part of the pod, it outlines the use of the most basic functions. Once you've read through that you can read about different events and widgets and such in the rest of the pod. I'll echo a previous poster's comments in saying that you should definitely also check out the widget demo.
Hope this helps,