The Visual Display of Quantitative Information by Edward R Tufte. 'The Da Vinci of data' was the judgement of one reviewer. This is an incredible book. Described as one of the top 100 technical books you must read. If you like that sort of thing of course. It is the best book I read this last month and beat out books in fiction and art categories - a rare feat.
It includes the groundbreaking work of people producing info-graphics long before the term was coined. The famous chart of Napoleon's disastrous campaign in Russia is included, sparklines, and a well worked set of principles for data display. Measuring data ink as a proportion of space, and measuring the 'lie factor' of charts are both extraordinary discoveries which render measurable what you have long suspected about poor graphics in mainstream news.
The reason for the read is that we are exploring new ways to present the ratings data from the Quality Product Research database in reports.