Here is a list of resources (compiled by our friend Marcel Vaz) on leadership. They are mainly a compilation of opinion pieces and research done on the matter. If you have any practical manual that you would like to share, this is the place for it!
Career focused:
https://blogs.scientificamerican.com/observations/why-scientists-should-have-leadership-skills/
https://www.sciencemag.org/careers/2012/03/enhance-your-career-leadership-skills
About leaders:
https://www.sciencemag.org/careers/2015/12/many-faces-leadership
https://www.nature.com/articles/d41586-018-07530-7
https://www.nature.com/articles/d41586-018-05146-5
https://www.nature.com/articles/d41586-018-05156-3
https://www.nature.com/articles/d41586-018-05156-3
Studies:
https://www.nature.com/articles/d41586-018-05143-8