In my own experience. I got really turned off by all the granola crystal woowoo. So I didn't use any "method" or podcast. I found that all that was really important is you're able to relax and calm down. (And if crystals help you with that, power to you). So just find something that helps keep you calm and you'll be okay. I would personally put more effort into learning about breastfeeding. But that's my experience, I admit I had a pretty easy birth.
I really appreciated the Mayo Clinic Guide to a Healthy Pregnancy book. It presented all the options and information in a straightforward, nonjudgmental manner. I also took a class on Labor and Delivery with my hospital, and the instructor really focused on the unmedicated pain management options the hospital offered. I intended to have a unmedicated birth, but I got an epidural and was very happy with it.
I liked Mindful Birthing by Nancy Bardacke. It was basically like it’s cool to have a plan, but it’s ok if it doesn’t pan out and you need medical assistance. (Thank goodness, too. My whole plan went totally tits up)
Maybe Pathways to Family Wellness magazines? I worked for a chiropractor that was Webster certified and he encouraged me to try other things before going straight for epidural. Reading those magazines between patients sometimes had good articles
Check out Bridget Teyler on YouTube :). She’s a doula and a birth educator and her content is great! She’s not anti-interventions, but she explains really well the difference between actually needing them versus convenience for the OB.
This doesn't help you with books, but in medical school in the Netherlands I was literally tought that unmedicated was best. Maybe try for articles from Europe?