I think a good place to start is with the first two Meditations of his Meditations on First Philosophy. In comparison with some other philosophers, Descartes is quite readable. The style is conversational, even playful at times, and his manner of persuasion is clear, methodical, and easy to follow. read more
The books of Descartes themselves are a very good starting point: clear enough, don´t need a lot of explanations. Discourse of the method and meditations of the first philosophy are the key texts. For advanced reader, Rozemond, Marleen, 1998. Descartes's Dualism. Cambridge: Harvard University Press is a good book. read more
10 Best Philosophy Books Of All Time To gain a good understanding of western philosophy, you have to cover the basic teachings of some of the most influential philosophers. These thinkers affected the course of history with their work, and the legacy of many of their studies are relevant now more than ever.Below we have compiled a list of 10 books everyone must read to gain a better understanding of western philosophy. read more
It is probably best to learn the definitions (as they are used in philosophy) of the following words: a priori, a posteriori, deontology, consequentialism, utilitarianism, empiricism, subjective, objective, espistemology, ontology, metaphysics, aesthetics, metaethics, analytic/synthetic. read more