What is logic? How best can I learn about it?

Logic is a very broad topic that includes rhetoric, fallacies, and many other tools. A good place to start is to examine things that can be explained or dismissed by logic. Start here: a href="http://changingminds.org/index.htm." rel="nofollow"http://changingminds.org/index.htm./a It should keep you busy for a few years :)