Marvelous book. Brilliant in its simplicity, but with lots of immediately actionable insights. I'm three-fourths through right now (it's a short read, maybe two hours?), and tremendously enjoying it.
It's using the term economics in the classical sense to mean household management, going through points about the nature of wealth, using assets wisely, using time well, living well, and so on. It's primarily a recollection of a dialog between Socrates and Critoboulus.
I'm reading this translation, which is free on Kindle and totally decent, though the spacing/layout of footnotes is a little messy.
It's short enough that I'd say just jump in -- the pacing starts a little slow, but there's actionable insights in there. Recommended.