I needed the book for my Decision Theory course at uni, its good to read and it takes the reader from zero all the way through the basics of decision theory. Surprisingly understandable even if you havent heard about its content before!
This is an elegant and highly readable introduction to decision theory. In addition to decision theory in the one-person sense, the book also covers game theory, social theory. While the focus is on normative theory, there is also a short overview of descriptive theory. Highly recommended.