Sweet A Field Guide to Modern Logic, 2nd Edition offers an innovative, friendly, and effective introduction to logic. It integrates formal first order, modal, and non-classical logic with natural language reasoning, analytical writing, critical thinking, set theory, and the philosophy of logic and mathematics.
This textbook is an introduction to various forms of logic, including symbolic logic as well as more informal arguments, such as ones that occur in debates. The book's strengths include simplicity and clarity. However, the books has some serious weaknesses. One is that its exercises end up being far too difficult. The instructional portions of each chapter are clear and simple, but then the exercises become fiendishly difficult. In my opinion, the authors did not prepare the student/reader to answer each exercise. Another weakness is that the book bounces around between symbolic logic (predicate, deductive) and written-out arguments that are diagrammed and/or outlined. It would be better to cover one form of logic and do it well then to go back and forth. Also, it doesn't really address informal logical fallacies, which are made so frequently and must be addressed.