I listen to a lot of podcasts. They make my workouts much more enjoyable. For the most part though, I only listen to ones about sports and more general podcasts about design, technology, and working from home. However, a couple of months ago, Enrico Bertini and Moritz Stefaner started Data Stories, a podcast on visualization. Enrico is a researcher in the area and Moritz is more of a practitioner, so it's a good contrast between the two.
Neither had experience producing podcasts before this, so it was rough around the edges at first. But each episode has been getting better. I highly recommend it.
In the most recent episode, with Andy Kirk, they discuss the most common question from people new to the field: how to get started. Go ahead and listen. It's a good one if you're itching to get your feet wet.
One thing I'd add (that maybe I missed as cars drove past me) is that it's important to establish what you want to learn visualization for. The purpose will change what methods to use and what software to learn. Monitoring server load for a web service is going to be different than say, designing an atlas.