I published a new tutorial that focuses on one function:
tidyr::gather(), which is used to convert data from messy to tidy:
In the tutorial I assume that you know the terms and just need help figuring how to get from A to B. If, however, this is all new to you, I suggest reading “Tidy Data” by Hadley Wickham, the seminal paper on the topic, which lays out the concept in detail.
Feedback is welcome!