!rant: What do I need to learn to move from developer to project manager?

You need to learn how to urge developers with calculating way too less time than a project needs.

To be serious: You need to learn how to make the exact opposite.
I think it's pretty much about experience. You should learn and experiment with different techniques.
I advise you to buy a book about this to get a overview over this topic. It's something you can't write in just a few sentences in my opinion.

Lobotomy.

To yoda you listen: "you have to unlearn what you have learnez"

Any good books in particular?

Above all else you need to learn how to say no to clients (in a diplomatic way, ofc).
There are few things more useless to both client and team than a spineless PM.

How to sell your soul to Satan?