Start with high-confidence zen books, then narrow by subgenre or adjacent topics.
Don't Worry
Shunmyo Masuno, Allison Markin Powell
The Way of Zen
Alan Watts, Alan W. Watts
The Three Pillars of Zen
Philip Kapleau Roshi, Philip Kapleau
Thoughts Without a Thinker
Mark Epstein
The Way of Chuang Tzu
Thomas Merton, Dalai Lama XIV
The Zen Teaching of Bodhidharma
Bodhidharma, Red Pine
The Unfettered Mind
Takuan Soho, William Scott Wilson
The Life-changing Magic of Tidying Up
Marie Kondō
Ordinary Wonder
Charlotte Joko Beck, Brenda Beck Hess
How to Connect
Thich Nhat Hanh, Jason DeAntonis