For any Google Search - be sure to limit searches to within the past year or so. R packages get updated very frequently, and many functions change or become obsolete.
- R Graphics: https://www.stat.auckland.ac.nz/~paul/RGraphics/rgraphics.html The best book about using base graphics
- R Graphics Cookbook: http://www.cookbook-r.com/Graphs/ or http://amzn.com/1449316956 The best book for using ggplot2
- STHDA: Statisical tools for high-throughput data analysis. http://www.sthda.com/english/
- Quick-R: Basic Graphs
- Quick-R: ggplot2
- Help lists