Theravada Buddhism
Rahula, Walpola. What the Buddha Taught.
Bhikkhu Bodhi. In the Buddha’s Words: An Anthology of Discourses from the Pali Canon
You can also read translations of the original suttas. The order I’d suggest for the four main collections of Suttas (called Nikayas) is Majjima Nikaya (Middle-Length Discourses), Diggha Nikaya (Long Discourses), Samyutta Nikaya (Connected Discourses), and then Anguttara Nikaya (Numbered Discourses; I found this the hardest one to get through).
Who Was The Buddha?
Bhikkhu Nanamoli. The Life of the Buddha: According to the Pali Canon
Hecker, Helmuth. Great Disciples of the Buddha: Their Lives, Their Works, Their Legacies
Armstrong, Karen. Buddha.
Manuals for How to Meditate
Upasaka Culadasa. The Mind Illuminated. This walks you through ten stages of focusing the mind then doing Vipassana.
Brasington, Leigh. Right Concentration. A classic manual on how to do jhana practice.
Rosenberg, Larry. Breath by Breath. Simple instructions for how to meditate.
Catherine, Shaila. Beyond Distraction. Not exactly a manual, but she synthesizes the Buddha’s teachings on how to avoid distraction in meditation.
Miscellaneous Great Education in Buddhism
Peck, Tucker. Sanity and Sainthood. Well I gotta put this one on here. I didn’t know of a great book on Buddhism and Western psychology, so I wrote one.
Macy, Joanna. Mutual Causality in Buddhism and General Systems Theory: The Dharma of Natural System. While not an easy read, this is an incredible treatise on what Buddha meant by Dependent Origination, and how this theory didn’t show up again in the world until the 19th century. Called general systems theory, it took over many (most?) fields of academic inquiry.
Salzberg, Sharon. Two books: Lovingkindness and Faith. The former is Sharon’s first book, which is mostly about metta meditation. The latter includes her own biography and how she wound up being the canonical Western authority on Metta.
Thanissaro Bhikkhu. The Paradox of Becoming. Like the Macy book above, it’s a bit erudite. It’s a description of how the Buddhist path first cultivates forms of addiction – like addiction to jhana – before this addiction takes you to a place where all addiction can be abandoned.