From the reviews:
This book has grown out of lectures on the subject by the author. ... it must have been fun for both the author presenting these courses on class field theory and the students taking them and eager to learn the subject. ... list of contents may give a good impression of how class field theory is developed in this book. ... each chapter is commenced by a short introduction describing what is going on next. I enjoyed seeing explicit examples and nice applications ... . (Jurgen Ritter, Mathematical Reviews, Issue 2009 i)
Class field theory studies abelian extensions of number fields and their completions. ... The clarity of the exposition and the many exercises ranging from routine to quite challenging problems make the book perfect for a first introduction to class field theory. (Franz Lemmermeyer, Zentralblatt MATH, Vol. 1165, 2009)
In a fast ride, running half the length of many competing volumes, Childress (Arizona State) employs a balanced mix of standard tools for a remarkably honed introduction ... . Good to read alongside fleshier accounts; probably more accessible ... . Summing Up: Recommended. Upper-division undergraduates through researchers/faculty. (D. V. Feldman, Choice, Vol. 47 (3), November, 2009)
This is a first introduction to class field theory. ... The author succeeds in making the material accessible by proceeding at a moderate pace. This relatively slim book is a good choice for anyone who wants to get an idea of what class field theory is about before tackling a more comprehensive textbook or monograph. (Ch. Baxa, Monatshefte fur Mathematik, Vol. 164 (3), November, 2011)