Not a mystery, per se, but Girl Sleuth: Nancy Drew and the Women Who Created Her by Melanie Rehak did win an Edgar Award for Best Biography. And, per its blurb, it was also a Chicago Tribune Best Book of the Year. I have to admit that Nancy Drew (and Encyclopedia Brown) got me hooked on mysteries even before I discovered Agatha Christie, so this looks like pretty interesting reading. And Girl Sleuth has now dropped to $2.99 at Kindle US.
Buy at Kindle US