Mikhail Popov, a data scientist at the Wikimedia Foundation, led a workshop on visualization literacy recently. A short guide from that workshop is now freely available online.
Beginner’s guide to visualization literacy
Shifting Incomes for American Jobs
For various occupations, the difference between the person who makes the most and the one who makes the least can be significant.
Think Like a Statistician – Without the Math
I call myself a statistician, because, well, I’m a statistics graduate student. However, the most important things I’ve learned are less formal, but have proven extremely useful when working/playing with data.