For actual depth and substance regarding information visualization, you should just read Tufte, since much of this article is obviously informed by it: http://www.edwardtufte.com/tufte/books_vdqi
+1 million. That book changed my life, at least as far as information presentation is concerned. It's that good. If you ever make a chart or a graph, you owe it to yourself and your viewers to read that book.
