As part of my Basic Economics series, I'd like to also direct anyone who is interested in learning more about economics to read Walter Williams' short Economics for the Citizen, "a ten part series on basic economic concepts". The series can be found here. A few examples of what you'll read:
"The first lesson in economic theory is that we live in a world of scarcity. Scarcity is a situation whereby human wants exceed the means to satisfy those wants. Human wants are assumed to be limitless, or at least they don't frequently reveal their bounds. People always want more of something, be it: more cars, more food, more love, more happiness, more peace, more health care, more clean air or more charity. Our ability and resources to satisfy all those wants are indeed limited. There's only a finite amount of: land, iron, workers and years in a lifetime."
"In order for specialization to occur, there must be trade opportunities. It wouldn't make sense for U.S. farmers to produce more grain than they consume or plan to consume if they couldn't trade it. Neither would it make sense for Japanese producers to produce more camera lenses than they consume or plan to consume. That's why trade opportunities are necessary in order for people to take advantage of specialization."
"Economic theory is broadly applicable. However, a society's property-rights structure influences how the theory will manifest itself. It's the same with the theory of gravity. While it, too, is broadly applicable, attaching a parachute to a falling object affects how the law of gravity manifests itself. The parachute doesn't nullify the law of gravity. Likewise, the property-rights structure doesn't nullify the laws of demand and supply."