Funked,
You want 'Spitfire: The History' by Morgan and Shacklady. ISBN 0-946219-48-6
Wing's of the Luftwaffe is pretty good by Eric Brown. ISBN 1-85310-413-2
'The Great Book of World War II Airplanes' is also a good one, it's huge! I know the title seems a bit cheesy, but it's a compilation of authors on a variety of aircraft, P-38, P-51, B-17, Hellcat, Corsair, Spitfire, Mosquito, Lancaster, bf109, fw190, Ju87, Zero.
ISBN 0-517-16024-2