In addition to the book Mr. May recommends, I’d suggest reading my favorite three.
The first is one I finished not too long ago, The Inner-Work of Leadership by Barry Brownstein. This is just a phenomenal book that has already positively impacted my life. The two main points I took away were an understanding of how the notion of distributed knowledge, which I was very familiar with before I read the book, impacts our workaday world; and the enormous value of putting your people truly first and tearing down the roadblocks preventing them from making the maximum use of that distributed knowledge.
The other two are Charles Koch’s The Science of Success and It’s Your Ship by Captain D. Michael Abrashoff.
My main advice for being a good boss? Get over yourself — you aren’t anywhere near as smart or good as you think you are. And defend and fight for your people like a cornered cat.