Also there's an easier way to find where @INC points to. Just enter perl -V on the command line, and @INC is listed as one of the outputs (along with trivia like what compiler was used to compile the perl you're using, library paths, etc.)
Any modules you install will end up in one of those paths when it gets installed. You can also put custom modules there to be found for other reasons. I've split up things like this for various weird reasons dealing with multiple perl versions on different install locations on the same machine.