If you are new to data science and learning the R language, let me recommend this new gem of a book, Business Intelligence with R, by my friendr (the term I just coined to describe R users who help each other), Dwight Barry: https://leanpub.com/businessintelligencewithr
Business Intelligence with R serves as a great cookbook that can save you hours of frustration learning how to get the basics going. Even if you're an old pro, the book serves as a handy desk reference.
Also, please consider the personal note that Dwight sent to all of his beta readers:
Perhaps most importantly, I've also decided to give all proceeds to the Agape Girls Junior Guild, which is a group of middle-school girls who do fundraising for mitochondrial disorder research at Seattle Children's Research Institute and Seattle Children's Hospital. While the minimum price for this book will always be free, if you're the type who likes to "buy the author a coffee," know that your donation is supporting a better cause than my already out-of-control coffee habit. :-)
Business Intelligence with R serves a greater cause.