Many people agree that it would be good for everyone to take an economics course in high school or in college. Usually, introductory economics courses only cover microeconomics, though. I have just gone through the core of the Macroeconomics textbook used in 14.02 (Principles of Macroeconomics at MIT). I think it would be more useful for the first economics course that people take to cover primarily macroeconomics, especially if it's going to be the only course in economics they ever take. The topics in microeconomics that should be covered are the supply and demand curves, the concept of marginal utility, and the production function. The rest of the course should be about macroeconomics. Macroeconomics would help people to better understand fiscal and monetary policy and how they impact unemployment and inflation. This would help people have a better understanding of current events and be informed voters.
The problem when people only take microeconomics is that people try to use the very simplistic results to make policy decision. For example, people conclude that markets are the most efficient methods to allocate resources so there should be fewer regulations. Price ceilings and floors always add deadweight loss so those should never be used either. Theoretical and empirical results from macroeconomics are much more directly applicable to explaining everyday events and informing policy decisions.