Did you know that you can find extensive documentation about the awesome ggplot2 graphics package for R at author Hadley Wickham's website? At 211 pages (including references and index) some would say it's almost book-like. I've heard from reliable sources that this PDF will no longer be available for download after Hadley's book ggplot2: Elegant Graphics for Data Analysis is published next month. So you might want to grab it while you can.
Hadley Wickham: ggplot2 book
