The Discourses of Epictetus (Greek: Ἐπικτήτου διατριβαί) are an account of the oral teachings of the 2nd century Stoic philosopher recorded by his pupil, Arrian.
The Discourses at Amazon.com
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).
Internet Archive: The Moral Discourses of Epictetus, translated by Elizabeth Carter.
Loebulus. L218 - Epictetus -- Discourses, Books 3-4. Fragments. The Encheiridion. PDF of public domain Loeb edition in Greek and English.
Standard Ebooks: Discourses, translated by George Long. AZW3, EPUB, KEPUB and Advanced EPUB formats.
University of Adelaide (Internet Archive): The Discourses of Epictetus, translated by George Long. EPUB, HTML and MOBI formats.
Wikisource: Greek text.
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.
Stanford Encyclopedia of Philosophy: Epictetus.
Wikipedia: The Discourses of Epictetus.
The Enchiridion - A shorter compilation of Epictetus' moral teachings by Arrian.
The Meditations of Marcus Aurelius - a self-examination along Stoic lines of a kind recommended by Epictetus.
Ancient Greek resources: Learn to read Greek classics in the original.