R
Where next?
This is the end of the tutorial.
By now, you have acquired basic skills that allow you to process your data with R to collect basic descriptive statistics, create plots and test the statistical significance of the observed trends.
But R contains much more. You can learn about the package ggplot2 to create elegant graphs you have fully under control, plyr for more advanced data manipulation, or lme4 for linear mixed effects models. Depending on your purposes, you may learn about new tests and packages to perform them, or you may learn how to write your own functions.
There are many wonderful sources to help you master R and statistics in general, both online and in book form (visit your university library to find out about them). To name a few, there are the R cookbooks by Winston Chang or Paul Teetor, the book by Andy Field, Jeremy Miles and Zoë Field, or a tutorial on TutorialsPoint.
Ultimately, however, the best way to learn R is to use it in your own projects.
As you have now finished the tutorial, you can download it as a PDF for future reference.