Jay Heinrichs' book Thank You For Arguing is a nice introduction to how classical rhetoric can be repackaged for life in the 21st Century. The subtitle of the book, "What Aristotle, Lincoln, and Homer Simpson can Teach Us About the Art of Persuasion," points to the wide-ranging nature of the book. Heinrichs sometimes comes off a bit too cute here and there, but the book as a whole is a superb introduction to the power of classical rhetoric.
The book is broken up into numerous chapters, each of which explains a piece of classical rhetoric, supplying examples and summaries. It's a very useful tool either to gain an introduction to the discipline or to refresh one's familiarity with the nuts and bolts of how rhetoric can work in daily life.
Here in this season of political upheaval, it is also a good handbook on how bad some arguments can get, even while those arguments persuade people who don't know how to think through arguments.