ggplot2 allows to build barplot thanks to the
geom_bar() function. The examples below will guide you through the basics of this tool:
It makes sense to make your barchart horizontal: group labels are now much easier to read
Control group order
Reordering categories in the barchart is a crucial step for an insightful figure: learn how to do it.
Basic R can build quality barplots thanks to the
barplot() function. Here is a list of examples guiding you through the most common customization you will need.