The Enchiridion or Manual of Epictetus is a short compilation of the ethical teachings of the 2nd century Stoic philosopher by his pupil, the writer and historian Arrian.
Free online texts
Internet Archive: The Discourses of Epictetus with the Encheiridion and Fragments, translated by George Long (1890).
Internet Archive: The Discourses and Manual, together with fragments of his writings, translated by P. E. Matheson (1916).
Loebulus. L218 - Discourses, Books 3-4. Fragments. The Encheiridion. PDF of public domain Loeb edition in Greek and English.
Standard Ebooks: The Enchiridion, translated by Elizabeth Carter. AZW3, EPUB, KEPUB and Advanced EPUB formats.
BBC In Our Time: Stoicism - radio discussion with Melvyn Bragg, Angie Hobbs, Jonathan Rée and David Sedley.
History of Philosophy without any gaps: You Can Chain My Leg: Epictetus - podcast by philosopher Peter Adamson.
Internet Encyclopedia of Philosophy: Epictetus.
Librivox: The Enchiridion - public domain audiobook.
Stanford Encyclopedia of Philosophy: Epictetus.
Wikipedia: Enchiridion of Epictetus.
The Discourses of Epictetus - Another, more extended account of his master's teachings by Arrian.
The Meditations of Marcus Aurelius - a self-examination along the stoic lines recommended by Epictetus.
Ancient Greek resources: Learn to read Greek classics in the original.