Being logical: A guide to good thinking, by D.Q. McInerny (2005). This book is a mere 130 pages. It is written clearly and concisely, the author deliberately seeking to write after the fashion of Strunk and White (which you should also read, if you have not).
McInerny lays out the basic building blocks of logic, quite simply. He dedicates a few pages to each basic argument, a useful form to expose the reader to logic, but lacking the depth of coverage if you really want to dig in deeply.
The author suggests that logic is a basic educational component missing from nearly all of our schools in modern society. I think he is right on. Given that, this book would be good for Logic 101. 4 stars.