"Mannock seems to have been a very complicated man. I'd like to read more about him than the short article at wikipedia."
Two good books on Mannock for you, Anaxogoras:
King of Air Fighters by Flight Lieutenant Ira 'Taffy' Jones, D.S.O., M.C., D.F.C., M.M.; 1934, Ivor Nicholson & Watson Ltd, London. Jones was a colourful character who flew with Mannock; his book was the first biography of Mannock to be published. It's a product of its times and some of the details are doubtful, but it captures the ' period atmosphere' of RFC/RAF service very well.
'Mick' - The Story Of Major Edward Mannock, V.C, D.S.O, M.C., R.F.C., R.A.F. by James M. Dudgeon; 1981, Robert Hale Ltd, London, ISBN 0 7090 5169 7. First paperback edition published 1993. This is a very good biography of Mannock, and his motivation and mental state is described in some depth.