Edward Tufte's book The Visual Display of Quantitative Information is a monumental book. He writes not about how to make your graphs look pretty, but how to display vast quantities of data and distill them down into useful graphics that communicate themselves effectively.

He provides examples of good and bad graphs, but more importantly, explains what exactly it is that makes those examples good and bad, and further generalizes it so you understand how to make good visualizations. If you don't want to shell out the money for it, it's probably at your library (remember those?).

Additionally, if I were you, I'd stay way from statistical approaches to displaying information unless you have some background or are willing to learn about it -- it tends to be highly technical and is probably too complex for what you're trying to do. Basic stats might help you, but not as much as Tufte will.