The textbook I currently use for my Introduction to Logic classes is Logic For Beginners, which I first authored in 2011. A second edition was released in 2013, and the third edition in 2017. I hope to get an digital version published soon.
If you are enrolled in my Introduction to Logic class, the best place to get the textbook is usually your college bookstore. For older editions, you can search online, or go to the publisher's website: Archimedes Publishing.
