I`m sorry, but I am no specialist on N at all and would not buy any book on him. He is just a great, black blot on the European landscape that I am forced to learn about on occasion.
I did once buy a copy of `Napoleon at Work`, by Colonel Vachee, London 1914, which I found interesting, particularly concerning his relationships with Berthier - Kevin will cry this down.
Owen Conneely`s `Napoleon`s Satellite Kingdoms` is very informative, as is `France Under Napoleon` by Louis Bergeron.
Apart from these works, I read postings on this site, snoop around the internet and that`s it.