Reddit mentions of Introduction to Logic: Predicate Logic (2nd Edition)

Free:

Stanford's Intro to logic - w/ Free online tools for completing exercises.

Paul Teller's Modern formal logic primer - w/ free tools for completing exercises

Peter Smith’s Teach Yourself Logic and other materials, like his reading guide

Katarzyna Paprzycka Logic Self-Taught - w/ free workbook

J. Ehrlich's "Carnap Book" - w/ free exercises & tools

Open Logic Project - and List of other open/free sources.

Not Free or Kinda Free:

Gensler's Introduction to Logic - Book not free, but Free online tools

Howard Pospesel's Introductions to Formal Logic (prop and pred) - Book includes useful software for additional logic exercises

In the logic classes I took (my professor always said he hated the textbooks), we used this book and this book. They weren't perfect, but they were a good start.

For a history of philosophy, I'll second the comments on Will Durant and Bertrand Russell's books. Also, Richard Tarnas, The Passion of the Western Mind, is a little more modern style and covers more of the 20th century.

For introductions to logic, Kant is pretty advanced. I'd start with Anthony Weston's Rulebook for Arguments for a short but fairly comprehensive explanation of the basics. For more formal logical analysis, I like Howard Pospesel's cartoon-driven explanations and exercises: Predicate Logic and Propositional Logic.