Richard Overy’s ‘Why the Allies Won’ gives the economic & industrial side of the conflict. Despite that, it’s not a dry tome. http://www.bbc.co.uk/history/worldwars/wwtwo/how_the_allies_won_01.shtml for a precis.
Murray Williamson’s “Strategy for Defeat: The Luftwaffe 1933-45” gives an overview of the European air war.
Oooh – it’s officially online for free http://www.ibiblio.org/hyperwar/AAF/AAF-Luftwaffe/