A few months ago at Barnes & Noble, I came across a useful set of reference tools called SparkCharts. They provide a basic outline of the major facets of all sorts of subjects. Thus, they can be a good refresher on many subjects that you would have learned in school, but which are important to still remember today.
Here are some of the ones that I picked up and found helpful:
- World History
- United States History Pre-Columbian to 1865
- United States History 1865-2004
- United States Government/Civics
- Western Civilization
- Geography
- Sociology
- Philosophy
Here are some other ones that I see also exist:
- Statistics
- Microeconomics
- Macroeconomics
- Constitutional Law
- Weights and Measures
- Western Art History
- Music Theory and History
Sparkcharts don’t serve as a substitute for reading actual books on a subject, but can be useful as a reference tool for giving a quick overview or refresher.