Suggest an order to read data science books
I guess its common to start with
 "An Introduction to Statistical Learning by Gareth James, Daniela Witten, Trevor Hastie and Robert Tibshirani" and then, if you want a deeper picture, move to
 "The Elements of Statistical Learning, by Jerome H. Friedman, Robert Tibshirani, and Trevor Hastie". 

I also really like the video course based on the first book, taught by Hastie and Tibshirani ( if im not mistaken) - a real gem in my mind. 
From my perspective its a good way to get both practical and teoretical background for machine learning.
Link to the course published at R-bloggers:
https://www.r-bloggers.com/in-depth-introduction-to-machine-learning-in-15-hours-of-expert-videos/