During my economics degree I found that the Oxford dictionary of economics gives you a pretty good TL;DR version of pretty much any economic concept or word you come across.

I have read Wages of Destruction without, at the time, more than an introductory level of reading on general economics (as in first year undergrad level), and found it fairly understandable.

Is there any specific section or concept you would like explained?

I commend you for reading the book btw, one of the best books on WWII ever written.

The book "The Wealth of Nations" by Adam Smith as a starting point.