Wikipedia gives a general introduction to the background and the structure of the Book of Deuteronomy. It is well worth reading it or the introduction to the book from any of the major Jewish commentaries such as the Plaut, Eitz Hayyim, the JPS or the Hertz Pentateuch to keep track of the themes and content as this sometimes gets lost in some of the details given.
You will also notice a different tone in the language. We will talk about that more when we get to the poetic sections.
