My hope is to be able to get my compute-bound Perl program to use more of the several "cores" in my cpu

If you post a Short, Self-Contained, Correct Example showing us a specific example of what you are trying to achieve and why, we can give better advice.

Meanwhile, you might find something useful in my long list of general references on this topic at Re: Threads or no Threads (Threading, Forking, Signals, Event Loop and Concurrency References).