- the biography of Napoleon by Cronin is pretty good, and also Isser Woloch "Napoleon and his collaborators, the making of a dictatorship, which will you inform how Napoleon could take the power in France.
- most of David Chandler's works
- also Digby's books as general reference works
And don't forget the french authors, as there is
- Louis Madelin - see the post of Bruno Nackaerts
- Tulard as Hans Karl mentioned
- Henri Houssaye
And I forgot the German and Russian (for instance Sokolov's book on the French army) authors .
As for magazines, there are no better ones than the French :
- Tradition and Tradition Hors Série
- Napoléon Ier
- La Revue Napoléon with its hors-series
really a must to have.
But for me it is very easy to speak, having some 1000+ books and magazines on the Revolutionary and Napoleonic period.