In my freshman year at University I took a course on Aristotle. I remember having this book in my bag everywhere I went, and chatting with all my friends about the cool and fascinating concepts found in here. Aristotle was probably the singular, most important influence on my philosophical development. It laid the foundation for all subsequent thinking and approach.
Aristotle is extremely important, and should be read by, really, everyone. Many think he is outdated and obsolete - I assure you this is not the case. While contemporary science and metaphysics has moved far beyond Aristotle, there are deep-truths to be found here. Namely, his approach to living a happy and virtuous life, I think is beyond is dispute. His concept of friendship has never been challenged by anyone aside from Montaigne. He was not only the first thinker to investigate everything he encountered, but his influence served as the basis for subsequent investigation for over 2000 years. His metaphysics and physics provide one of the first rigorous studies of ontology, and many of his notions we still think according to - whether or not we realize it. When you read Aristotle, his notions feel very basic and 'common-sense' - this is because much of our thinking has its roots in Aristotle.
Even if you don't buy into his Ontology, understanding it is an absolute necessary prerequisite for understanding all subsequent metaphysics. Most importantly, I think the PHYSICS and METAPHYSICS are the singular most important philosophical texts, next to Marx' Das Kapital. Many people regard the Republic as the most important philosophical text of all time (and antiquity at the very least), I believe those two texts are far more important (that is not to undermine the importance of the Republic or the works of Plato). The reason being is: for Aristotle, and all subsequent philosophy until the rise of Catholicism and the Scientific Revolution (namely, Galileo) science and philosophy were one and the same. The two were not separate; and nowhere is this more evident in the Physics and Metaphysics, as well as in De Anima. Rarely, especially now, do philosophers or scientists take this approach. There is a schism between disciplines now, reinforcing our categorical and mode of thinking - thinking in the manner of verstand. Usually, this is only overcome when there is a philosophical critique of science; but this is not a unity of science and philosophy proper. What we need is a resurrection of the unity of science and philosophy, rather than propagating animosity between the two subjects; an animosity grounded in not only method, but ideology. Merleau-Ponty is someone we can all learn from, who made attempts to not simply synchronize the two, but see them as one and the same. Philosophy and Science are one and the same; and depending on the telos of your investigation, both fields are striving for something fundamentally the same. Anyway, I digress...
This is a very good compilation of Aristotle's essential works. Ideally, you want the complete works of Aristotle, but many of the works included in the complete works which are not in this edition are those which aren't read by most casual and lay-readers. This text, however, provides a nice, well-rounded, comprehensive collection of Aristotle's most widely-read works: namely the organon, de anima, physics, metaphysics, rhetoric, poetics, politics, and of course the nicomachean ethics. There are little excerpts from history of animals, parts of animals, on generation and corruption, on the heavens, on dreams, and others. Usually, this text is also sold for a reasonable price, in which case you can't go wrong. It has a nice, flexible binding, and is easy to navigate through.
Good text for anyone interested in Aristotle. I would actually recommend getting this edition before the complete works if you are just getting a taste for Aristotle.
Regarding the content: well, it's Aristotle!