Socrates is unique among philosophers, not just for his place among the early Greek philosophers, but also for the fact that he is the most famous philosopher to never write his own books. What we know of Socrates comes from contemporary accounts and students, most particularly Plato.
Set in 399 BCE, the Phaedo is a reconstruction of Socrates final conversations with friends on the day he died. We do not know when this dialogue was written, but it was probably before The Republic (Plato's most famous work, also featuring the figure of Socrates). Like The Republic, this dialogue features a well developed theory of Forms -- these are introduced gradually here, slowly filling out the details of each step. This develops the story of the caves idea from Plato's earlier work in epistemological, metaphysical, moral, and semantic terms. Plato also advances the 'imperfection argument' here -- the idea that when we sense something, it is never perfectly the thing we are thinking of, and that idea or standard to which we relate what we see, hear, feel, etc. is tying into a more perfect Form.
However, the idea of the soul is rather less developed here than in The Republic. The soul is simply mind, or intellect - all emotions are here placed as bodily aspects. This is rather Pythagorean in a fashion, that only the soul grasps the perfect Forms, and so should consist of nothing but reasoning ability, for emotions distort and cloud the perceptions and judgments.
In the end of the Phaedo, we witness Socrates drink the hemlock, without fear or trembling, as a philosopher should know the value of life and welcome death with a firm hope. The story is almost religious in nature here.
However, there are other possible readings, and this edition opens these up. This translation is part of a series done by the translators and Focus Publishing of the Plato dialogues. It has an introduction and a glossary of Greek terms, as well as a brief bibliography. The translators avoid a clunky translation by doing some interpretative work, but explain their reasonings in the introduction. They argue in the introduction against many traditional renderings of Phaedo, and as such provide an interesting counterweight to the prevailing editions available.