For starting points, you can look at any module that's probably included with perl to get an idea of what goes where.

Of late, one consideration is between putting all the module documentation in one block (typically at the end), or in separate blocks, such that function calls have their documentation right next to them. To perldoc, this makes no difference, but it all depends on your programming style and how you comment functions.

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Dr. Michael K. Neylon - mneylon-pm@masemware.com || "You've left the lens cap of your mind on again, Pinky" - The Brain
It's not what you know, but knowing how to find it if you don't know that's important