I have uploaded the instructional materials for my Advanced Data Analysis course on mediation and moderation for the Master in Communication Science at the University of Vienna at this link.
The material includes a brief introduction to R and RStudio, a short summary of exploratory data analysis and linear regression, and sections dedicated to mediation, moderation, and mediated moderation using the Hayes’ Process software.
It is based on the excellent book of Andrew F. Hayes Introduction to Mediation, Moderation, and Conditional Process Analysis, an invaluable resource to learn these techniques, written with rare clarity.