Historically the learning curve for R has been a real impediment to developing new users. R has a steep learning curve because R exists in an environment between statistical programming and computer programming. This makes it a little out of the comfort zone for the typical types of people who use it.
Lately that has begun to change. The introduction of RStudio to the R world has made the use R so much easier to deal with by automating all the support tasks needed to productively use R. Gone are the days of using a mashup of text editors, command lines, bash programming and multiple open windows to do an R project. Now it is all clean and organized through Rstudio so all the R user has to worry about is the Data and programming in R.
Coursera has done a good job of bring up completely new users to R with their Data Science Specialization. If you are starting from ground zero it is the way to go. It will get you started in a solid and robust way. The only issue is that Coursera is nine one month classes. If you have some experience in this area nine months is too long to get up to speed, and may be painful review rather than true learning.
The solution is Jared's book. If you have had some basic programming or some statistical background you can start doing real work right after reading this book. This is a week at most not nine months. No Jared book does not cover all the things a user would do in R, but it covers the 20% of R that users do 99% of the time. There is no exotic or special here. It is just that basics to get rolling, and that is what new users need.
So if you have not done much work in R, and want to get off to a quick start with some solid basics I would strongly recommend R for Everyone.