There are many resources that help you to design data visualizations in ggplot2. However, few resources guide you on how to build a ggplot step by step. For beginners the official documentary might be too daunting, for academics, Excel is often an easier solution to design data visualizations for conferences (think about adding p-value with horizontal brace).
From a pedagogical perspective, letting beginners solve problems by themselves is often not a good idea. Rather, learners profit from extensive guidance, especially at the beginning of knowledge acquisition.
There are some notable resources, which provide novice students of ggplot2 with such an extensive guidance. For example, Cédric Scherer is an awesome ggplot2-wizard who wrote a superb article on how ggplots are created step by step. And there is Gina Reynolds who creates stunning presentations on how to create a custom ggplot..
My goal with this website is to carry on the work of these people and establish a common resource that helps everyone to create a versatile set of data visualizations in ggplot2.