Here are some of the Stoicism books I’ve read, and indeed the ones that someone seeking more information will likely encounter first.
For a more extensive list, check out the one curated by Massimo Pigliucci here.
A Guide to the Good Life: The Ancient Art of Stoic Joy, by William B. Irvine
How to Be a Stoic: Using Ancient Philosophy to Live a Modern Life, by Massimo Pigliucci
The Daily Stoic, by Ryan Holiday
Ego Is The Enemy, by Ryan Holiday
The Obstacle Is The Way, by Ryan Holiday
Rome’s Last Citizen: The Life and Legacy of Cato, Mortal Enemy of Caesar, by Rob Goodman and Jimmy Soni
Stoic Warriors, by Nancy Sherman
Writings by Stoics
Meditations, by Marcus Aurelius
Discourses, Fragments, Handbook, by Epictetus
Letters on Ethics: To Lucilius, by Seneca
(Free PDFs courtesy of Tim Ferriss can be found here)