Packages

swirl Interactive introduction to R so you can learn R, using R.
tidyverse Core package to load packages dedicated to working with tidy data frames.
agricolae package to help you design and analyze agricultural experiments (RCBD design, post-hoc tests)

Online work-at-your-own-pace courses

Working with Data in the Tidyverse Data Camp course for using the tidyverse for data manipulation. Uses data from the Great British Bake Off!
Epidemiology & Data Science plant pathology & data science course by the Garrett Lab at University of Florida. Great exploratory sections on using R for data science in plant pathology.
Sampling, Data Management and Visualization UNL Course lead by Dr. Drew Tyre
RStudio Cloud Data Camp Courses browse available data camps for learning to work in R

R for Beginners to build a strong foundation
RStudio Cloud Primers great tutorials to learn a variety of R skills
RStudio Cheat Sheets great visual maps for data analysis (highly recommend the dplyr, data import, and ggplot2 sheets!)
R style guide to make sure your code is beautiful because when your code is easy to read, your future self will thank you.
R for Data Science how to structure, transform, model, and visualize data, written by the creator of the tidyverse
CRAN task views Grouping notable packages in specific topics such as Phylogenetics, Time Series, Experimental Design, etc.
Happy Git and GitHub for the useR a long-form tutorial on working reproducibly in R and RStudio with Git and GitHub
Googling for Help tips for googling for help, section of data carpentry for biologists course
R Stats 4 Ag great resource for how to use R to analyze statistical designs that are commonly used in agricultural experiments

Top 50 ggplot2 visualizations for how to build (with code!) the most common ggplot2 visualizations
R Graph Gallery for data viz inspiration and reproducible code
FlowingData for excellent tutorials for getting started with data visualization
VisualisingData for tutorials on more advanced data visualizations

ComBEE @ UW-Madison bi-weekly study groups for R and Python during the semester. All levels welcome!
UW-Madison CALS Stat Consulting For one-on-one help with data analysis from design to results interpretation
Lynda.com Basically youtube for software training. Full library of self-study software tutorials, free for UW-Madison students

Twitter is a great resource for getting help in R. You can browse the #rstats hashtag to see what’s going on.

These accounts are great to follow to see what’s going on in R

@RLangTip tweets out useful tips and tricks to use R
@dataandme aka Mara Averick often tweets out links to useful tutorials in R
@juliasilge data scientist at StackOverflow
@_inundata aka Karthik Ram, a data scientist at the Berkeley Institute for Data Science
@JennyBryan currently works at RStudio and very concerned with usability
@hadleywickham creator of the tidyverse and cheif data scientist at RStudio

Upgrading R on Windows can sometimes be frustrating. The intstallr R package helps with this process.