I’ve found that the best way I learn something is by getting my hands dirty (i.e. attempt a problem and learn the technicalities along the way). Given that a lot of statistical analyses used in bioinformatics are provided as packages in R, it makes sense to learn the innards of R. For example, by simply learning about how results are stored as R objects one can further analyse the results or manipulate the output (this seems like a trivial example but in the past I just relied on the functions provided within a statistical package to prepare my results).
You can click on the R tag, to retrieve all posts related to R.
And lastly, just with the rest of my site, I use this site as a learning tool for me. Please view everything with a grain of salt.