A new book called The Wal-Mart Effect by Charles Fishman has recently been released which provides richer details and a more balanced narrative on the way our entire economy continues to be subjugated to this behemoth. You can read a review in the USA Today.
This book doesn't particulary take sides or even point fingers, but more simply lays out some aspects of how your world is increasingly impacted by this company in ways you might not have imagined.