The following books and online learning resources can teach you additional skills to get the most of out the lessons found in this site.
R and RStudio
Introduction to R for Data Science by edX
R Tutorial by Quick R
Leaflet for R by RStudio
Spatial Analysis Resources
Introduction to Mapping and Spatial Analysis with R
Spatial data manipulation by R Spatial
Spatial Cheatsheet by Geospatial Data in R and Beyond
Transportation Analysis Resources
Public Transportation Course Modules by Kari Watkins, Jeff LaMondia, and Candace Brakewood
Public Transportation Systems by Nigel Wilson, John Attanucci – MIT OpenCourseWare
Transit Management by Nigel Wilson – MIT OpenCourseWare
Books
Data Wrangling with Python by Jacqueline Kazil and Katherine Jarmul