Well if you want to take advice from someone who did it, here you go.
I guess for backstory, I'm 46 and have been programming since I was 12. I caught the .COM onramp as a hot shot programmer/architect. 12 years CTO experience. About mid career I was growing hyper aware that being a smart introvert just meant people were likely to walk all over me. At the same time I picked up on this common experience where IT people and marketing people rarely get along. It's like two different worlds, different approaches to life - logic / vs emotion. (Before anyone argues with me, I know there are exceptions, but overall this is significantly common in my own experiences)
The final straw for me was a company retreat where we all went to a resort.. I spent the entire week in my hotel room watching the rest of the company swim while I was fixing servers and dealing with customer issues.
Anyway, to shorten it up a bit - I decided to learn sales and marketing with the intention of becoming good at it and better understanding that side of the business.
So I picked up some books, here they are in the order that I consumed them.
Influence - Robert Cialdini
Tribes - Seth Godin
How to win friends and influence people - Dale Carnegie
In my IT career I'd done pretty well up til that point.. but I seemed to always have a chip on my shoulder with marketing/sales.