Reddit mentions of Introduction to Logic: Propositional Logic, Revised Edition (3rd 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

[This is actually a great book] (http://www.amazon.com/Introduction-Logic-Propositional-Revised-3rd/dp/0130258490) and comes with software that you can use to test your new skills.

I would read up on it and use your new logic sword to slay those who try and argue with you while out on the town courting ladies at the bar. In your next politically charged conversation, whip out some logic and prove the tenants of your opponents arguements false, sit back and watch the ladies swoon.

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.