Copi's textbook lays out all of the basic concepts in symbolic logic necessary for more advanced work as well as many of the fundamentals of discrete mathematics. Some people have commented that his treatment is outdated, but a thorough understanding of chapters 6, 8, and 10 should equip anyone to understand the newer forms of notation. Chapter 7 is notably excellent but seemed out of place. As the most advanced of the whole book, it relates more than later chapters to the "further reading" topics. Proof of the redundancy of "indirect proof" (chapter 3?) and multi-modal logic were other very notable highlights.
A few criticisms: Copi explains the quantification rules of first order predicate logic rather tersely for a primer, and I was glad to have used Virginia Klenk's book originally when encountering these concepts. (Although Klenk's explanation of EI and UG are non-standard and will make transitioning very confusing if you cannot grasp the validity of her methods.) The index only provides a step by step answer key for selected exercises, which leaves stuck if Copi has solved only one problem to demonstrate some concept which still isn't clear. Finally, the binding on this book is just cheap. On all copies that I have encountered, the glued pages were breaking away from the spine after only a few months of regular use. Perhaps the newer edition is better, but I haven't had experience with it.
Despite these rather minor shortcomings, Copi's work unfolds almost as systematically as the content it teaches. This is an excellent introduction.