R is one of the top-rated problem-solving tools for machine learning, data science, data analytics, data mining, and statistical analysis. R’s popularity has resulted in the development of thousands of tutorials. Unfortunately, it’s easy to get lost in a maze of too much information. Valuable time is spent trying to find exactly what is needed to solve problems. The end result is frustration and difficulty understanding what’s important. Just Enough R! gives just enough of the R language and machine learning methods to minimize stumbling blocks and cut through the maze. This chapter paves the way for problem-solving with R. It offers an introduction to supervised and unsupervised machine learning strategies and provides foundational material for model evaluation. This chapter concludes with a brief discussion of ethical issues central to data analysis.