I haven’t yet tried this, but it looks like a nice package.
In one recent project I needed to draw several maps and visualize different kinds of geographical data on it. I found the combination of R/ggplot/maps package extremely flexible and powerful, and produce nice looking map based visualizations.
Here is a short tutorial,
monospacefont indicates the code you need to run in R. You probably need some basic understanding of R to work through this tutorial.