This is volume one of a two volume set. The second volume is "Epictetus : Discourses, Books 3 and 4 (Loeb Classical Library, No 218)". The contents for both volumes are as follows:
Discourses, Book I
Discourses, Book II
Discourses, Book III
Discourses, Book IV
The first thing worth noting is that although the titles of the volume refer to just the Discourses, the set is really a complete set of extant works, including fragments from other sources as well as a complete copy of the Encheiridion.
As is typical for the Loeb classical library books, the volumes are physically small, and the original text (Greek, for Epictetus) is given on the left hand page, with the English translation on the right.
The Introduction gives a brief biography of Epictetus and background information concerning Stoic philosophy. The Bibliography (which contains an update note from the original 1925 edition) gives the state of Epictetus scholarship. In the actual texts, footnotes are abundant and explain unfamiliar names, places, difficulties with translation, uncertainties about the source text, and Epictetus' quotes from earlier writers are more fully referenced. In summation, the background material supplied with these books is excellent.
As for the texts themselves, they were not actually written by Epictetus, but were notes taken by Arrian, one of his students (not unlike the Nicomachean Ethics, which were notes taken by a student of Aristotle). The Discourses are quite lively in style; Epictetus' personality and teaching style comes through vividly. This is not true of the Encheiridion, which Arrian abstracted from the Discourses and which had the life wrung out of it in the process.
The Discourses are not a well-organized body of work, as their origin might suggest. They are repetitive, and points that should have been grouped together logically are dispersed throughout.
The content is almost entirely ethical. Epictetus emphasizes the spark of divinity within man - that a man should always behave honourably. External things, such as wealth and power, are not things to be valued - they can be lost at any time, and are not worth a man's honour. Because his teachings are ethical, Epictetus is not concerned with what a man knows, but how he lives. The point isn't to understand his philosophy (which isn't hard), but to live it (which is).