Oh boy oh boy oh boy - I am so excited at learning that a new Then & Now book is coming out soon. The Battle of France covers the RAF, and others, from the start of the war through to the end of Dunkirk. I can't wait and is definately on my (post) Christmas list.
It should be an excellent compliment to Shores' Fledgling Eagles, Cull's Ten Days in May, and Franks Air Battle for Dunkirk (all excellent books anyway):
http://www.afterthebattle.com/boffranc.htm