IMHO one of the better books to come along in awhile that explains (or at least tries to make sense of) modern economics is "The Origin Of Wealth" by Beinhocker It's not an academic text, but it has a more modern slant, including ideas about how non-linear dynamic feedback systems and game theory, alter the predictability of outdated classical economic theory. An example of modern approaches, shows how mandelbrot followers have pretty much outdated ideas that markets are random. In reality, they are worse than random (gaussian). No wonder it's so hard to beat the system.
Bingo. Adam Smith was the first (IIRC) that explained free markets mean that me making more money than you doesn't degrade you at all. In other words, free markets do not mean (contrary to most thought) that if I take all the slices of pizza, you have to feed the box to your family. Smith explains that if you are a cattleman, and I grow apples then you have lots of beef and I have lots of apples. We can get together and trade apples for beef. You'd way rather have a few bushels of apples than another side of beef, and I'd way rather have some nice steaks than several bushels of apples. We both gain from the trade. In other words, the trade itself enriches us both. By trading, we have produced wealth. We are both better off than before, wealth has been created by trading. Understanding that simple fact will put you far ahead of many in econ.
The 1996 article in the New Yorker : "The Decline of Economics" is a good read. Economists discuss relevance of their profession What is taught or perceived as logical only applies in their universe. One example is the erronious belief that raising the minimum wage leads to higher unemployment as mentioned in the link above. Or better yet, in trade class, what happened to the reciprocity that was supposed to occur with all the outsourcing of the past 7+ years? Buts to be more forgiving to a field that has predicted 15 of the last 4 recessions, lets say economics is an ever evolving field trying to catch up with the real world in terms of explaining certian phenemona. The sad part is when the economists have a grasp on it, the world changes. If you like history with numbers, this is the field. You want to make money following the economy, take finance or statistics.
I enjoy econtalk: http://www.econtalk.org/ This is a good place to start: http://www.econtalk.org/archives/2007/04/bogle_on_invest.html The legendary John Bogle, founder of the Vanguard Group and creator of the index mutual fund, talks about the Great Depression, the riskiness of bond funds, how he created the Index 500 mutual fund--now the largest single mutual fund in the world--how the study of economics changed his life and ours, and Sarbanes-Oxley. At the end of the conversation, he reflects on his life and career.
Read: "The Economic Way of Thinking", by Paul Heyne, et al. That will get you started for sure, and maybe that should more than suffice. Enjoy.
They are in business to make a profit. Besides, their shareholders like it when the make a profit. Why are you in trading? Make sure to keep your profits down, that way people won't get mad at you.