The barplot function has a number of optional parameters. It might be interesting to play with a dataset and the parameters.

When you are displaying a word cloud, the function might complain that some words might not fit. Determine whether there is a way that this can be overcome.

What is the best way to determine the number of bins to be used in the hexbin function?

It was very unclear when producing a stacked bar chart as to how to organize the data to arrive at the correct result. Select a dataset and produce a stacked chart that meets your needs.

There are several packages to produce plots. How would you select one of the packages to use for your plotting needs?

If there was a package that extracted just the text from a web page, that would be of tremendous use for R programming. Investigate whether anyone has made such a package or at least taken the initial steps.