A very intuitively interesting book by the economist Thomas Piketty is “Capital in the twenty-first century”. He is called the modern Karl Marx, for his focus-shifting ideas. Purchase it at Amazon.
Some books on Economics, that must be read at some point.
While some are good references always, some can be read to understand some points of view. If books are available for free, as e-books, they are listed here too.
(While some reviews are my own, others are sourced from the site where they are available to read or to purchase.)
Summary from Amazon.com: “Boehm-Bawerk surveys and critiques failed theories of interest from antiquity to modern times, presents a full theory of the structure of production, and defends the importance of capital in production and time in the determination of the interest rate.”
Buy it here: http://www.amazon.com/