- "Enchiridion" of Epictetus.
- "Meditations" by Marcus Aurelius (my personal favorite that I keep reading over and over).
- "Letters from a stoic" from Seneca.
It's not a lot of authors but they're pretty dense and should keep you busy for a long time.
For buddhism, it's a very vast subject, but I'd start with:
- "Siddhartha", this is a novel but will give you an overview on the buddhist system of thoughts. It's also very well written and inspiring.
- "What the Buddha Taught", also an introductory book on buddhist toughts.
- Another introductory book is "Buddhism for Beginners".
From there, and based on your interests that you will discover along the way, go into the "suttas" which are the religious texts. You may even want to go to a time before buddhism with the vedas and the Upanishads that have so much to teach us.
There are many schools of buddhism, some closer to what we'd call a religion in the west while others purely philosophical (without any emphasis on a god). Zen buddhism is yet another category, where the teaching is based almost entirely on mediation alone but it's the exception, even if in the west we often think buddhism = meditation, but it's not so.
So, as you can see, it's more a tree than a line and you'll figure it out as you go if it resonnates with you and how deep you want to go.
The Daily Stoic by Ryan Holiday is the book that I read daily (it has an entry for each day) for the past 5 years and has helped me immensely. I tend to write one sentence in it after reading it, and then compare to all the previous one's I wrote - useful for uncovering (bad) patterns.
