This month I recommend the book by Cardinal Dulles titled Magisterium. If you want a genuine understanding of how the Church teaches doctrine and dogma then you will not want to be without this book. It also clearly defines how the Church defines infallibly and what words in Church documents mean like "irreformable" and "definitively" . In this day and age where every form of attack is made upon the Church Magisterium, every Catholic should have this work on their bookshelf, or better yet, on their nightstand for daily reading. Amazon has it.