Why I read?
The easiest and cheapest way to become a learning machine is to read more books.
Let me put it this way: is it worth spending $10 USD on a book that tells everything a person X has learned on Y for his whole life? I believe so.
In addition, I’ve done the “math”. Reading for 15-20 minutes a day will help you finish reading dozens of books a year.
Amazon is where I buy books. If you can buy a physical book, I strongly recommend that. Go for the Hardcover or Paperback formats. Nothing beats the smell of papers, flipping the pages, highlighting with a marker, and placing your favorite book on a visible shelf as a reminder of its principles.
Otherwise, get yourself an e-Reader (like Kindle) so that you can open eBooks (PDF, ePUB, azw3).
I’m using Goodreads to track my reading and revisit my highlights.