[Blahah]

Anything from the Harvard Negotiation Project [1]. Their books set the standard for universal, transferable, actionable, and evidence-based advise about how to optimise social situations for the benefit of everyone involved. They have online classes for various different skillsets and situations. Almost every mentor I have has recommended either the project as a whole, or a specific resource of theirs, to me.

Just in general I want to commend you for taking the time and energy to learn about this. It's a tragedy of the modern world that highly skilled people tend to be promoted into management roles and then stagnate, so that many tech organisations end up with people who are great at their specialism and terrible at managing people in managerial roles. Taking the initiative to really try to understand and excel at management is going to benefit not just you, but everyone who works with you. Bravo.

1: https://www.pon.harvard.edu/category/research_projects/harva...