The podcast I’ve found to be most helpful (and entertaining) is Writing Excuses featuring Brandon Sanderson, Dan Wells, Mary Robinette Kowal, and Howard Tayler. I’ve been a regular listener for the past few years and I’ve learned a lot from their wisdom.
You can also visit their website here.
And an honorable mention goes to Mur Lafferty’s I Should Be Writing podcast.
If you’re serious about a career in writing, improving your writing, and the business side of writing, I urge you to check out both podcasts.