Andrea: 

You might find these interesting

Pearce, Susan (1995), On Collecting, An Investigation into Collecting in the European Tradition, Routledge

Pearce, Susan, (1992), Museums Objects & Collections: A Cultural Study, Leicester University Press (for an account on the psycological and social reasons why people collect)

Pearce, Susan (1996), Experiencing Material Culture in the Western World, Leicester University Press

Elsner, John and Cardinal, Roger (eds.) (1994), The Cultures of Collecting, Reaktion Books

Belk, Russell W. (1995), Collecting in a Consumer Society, Routledge