- The Tao Te Ching, especially Ron Hogan's translation (freely downloadable here: http://beatrice.com/wordpress/tao-te-ching)
- The Diving Bell and the Butterfly, Jean-Dominique Bauby
- Getting Things Done, David Allen
- Gimp, Marc Zupan
- Thinking in Systems, Donella Meadows
- Leadership Step by Step, Joshua Spodek (full disclosure: me, https://www.amazon.com/Leadership-Step-Become-Person-Others/...)
The suggestion I consider more valuable is to focus more on active behavior than relatively passive reading. Of course, still read. But it's easy to read more and more, telling yourself you're getting more perspective. You are, but nothing changes your perspective like actually moving.
Even if you don't know what will work best -- meditation, fitness, art, music, travel, cooking, gardening, starting a business, etc -- starting with something, even if you soon abandon it, will lead you to things you love and that develop you faster than reading alone. Plus activity will make what you read more meaningful.
I include my book because it's specifically a book of exercises that lead to developing social and emotional skills designed to build on each other.
Note that one of its foundations is that developing social, emotional, expressive, performance-based skills takes practice and rehearsal to go from mechanical practicing, like playing scales, to effortless, genuine, authentic self-expression. The same as in learning to act, sing, play an instrument, play a sport, military, and so on.
The book gives you exercises. It's not for everyone. Just reading it will help you appreciate the skills. Practice will lead to growth.