Some useful R code examples on graphics are:
Learn R Toolkit:
It contains PowerPoint slideshows, videos, R scripts and data files to help Excel users move up to R. R code examples are provided for panel charts, conditional format, dot plot, box plots with or without points, and fully annotated histogram charts.
It is composed of 5 modules:
Module 1: Installing & Setting Up R
Module 2: Compare R and Excel Worlds
Module 3: R Script Basics
Module 4: R Charts
Module 5: Box, Dot, Histogram, Strip Charts.
Using R for Advanced Charts:
It presents examples on lattice plots, step chart, boxplot, trend chart, panel chart, etc.
Peter’s R Programming Pages:
It presents R code examples on various R plots, including 3D bar charts, matrix contours, microarray heatmaps, network graphs, scatter & pairs plots, Ramachandran (phi/psi) plots, and linear models.
Slides on R Graphics by Paul Murrell:
It provides many details on advanced graphic controls, such as margins, graphical parameters, grid graphics and lattice.