A good CPAN distribution will have several tests, conventionally in the t directory. For example, on the JSON page, follow the MANIFEST link. I see roughly 50 test files. In these files, there are examples of how functions and methods are called (specific values passed to those functions), and examples of what is returned from functions.

Some CPAN distributions have examples directories ("eg", "bin" etc.) which consist of short command line utilities for using the modules.

Look at the source code itself. Sometimes authors embed helpful comments.

If you want more examples of usage, try a Super Search.

If you start using a module, and you find the POD inadequate, please submit specific enhancements via RT. CPAN is not just a spectator sport; you can participate too. If you include a patch, that increases the chances of the documentation being improved, not just for you, but for the whole community. Even if the patch is not applied by the author, the RT report is visible to everyone.