Also searching google.com and groups.google.com for the module, will often reveal many code snippets to demonstrate usage. I find a good working example gives me a better start than the perldocs. You will find the quailty of the perldocs vary in quality, and some are of little help in explaining the actual working of the module. Gtk2 is particularly gruesome, the perldocs are auto-generated from the c code, and leave you helpless to figure out usage. But google for "Perl Gtk2 tutorial" and you will find really good reading.

Also, always look at any demo or .t (test) scripts that come with the module, they show proper usage.