Very good, in-depth source:
John L. Morgan, Jr., “The Army of Catalonia. Organization, Operations, and Logistics, 1808-1814” (Ann Arbor, Michigan: UMI Dissertation Services, 1995)
He has an article based on the dissertation, but not as detailed. of course:
John Morgan "War Feeding War?: The Impact of Logistics on the Napoleonic Occupation of Catalonia"
The Journal of Military History, Volume 73, Number 1, January 2009, pp. 83-116