[This is note to myself, just starting to read economics, based just on quick internet search]
The standard beginning graduate school microeconomics textbook is Microeconomic Theory by Andreu Mas-Colell, Michael D. Whinston, and Jerry R. Green (Oxford University Press).
Regarding macroeconomics, the choice is not so clear. I ended up picking two: The Foundations of Modern Macroeconomics by Ben J. Heijdra and Frederick van der Ploeg (Oxford University Press) and Recursive Macroeconomic Theory by Lars Ljungqvist and Thomas J. Sargent (MIT Press).
A Guide to Econometrics by Peter Kennedy (Wiley – Blackwell) provides a useful orientation to mathematical methods. The Theory of General Economic Equilibrium: A Differentiable Approach by Andreu Mas-Colell (Cambridge University Press) is more advanced.
For general, non-mathematical, introductions I like Basic Economics 3rd Ed: A Common Sense Guide to the Economy by Thomas Sowell, though it’s somewhat longwinded. Russell Roberts’ didactic novel The Price of Everything: A Parable of Possibility and Prosperity and the Friedrich Hayek collection, The Essence of Hayek, are well worth reading.