Oh, where to begin?
Completely at random:
Just finished reading all 4 of Martin Middlebrook's "eyewitness accounts" of famous WW2 bombing raids. It has really opened my eyes to what boming in WW2 was really like for both sides - in the air and on the ground. The ones on Hamburg and Nuremburg are particularly good.
For lighthearted flying yarns I like Neil Williams' book "Airborne".
L. Scott Berg's biography of Lindbergh is a fascinating read, for the flying and the social history.
"The Bishop's Boys" by Tom Crouch is a great biography of the Wright brothers.
The Science Museum publishes a great little book by Andrew Nahum about the history of (WW1 era) rotary engines. Dispels many myths.