Who first started the idea of classifying?
Carl Linnaeus started the idea of classifying. http://en.wikipedia.org/wiki/Carl_Linnaeus
Method to group organisms.
Carl Linnaeus did the Binomial Nomenclature method to group organisms. Binomial nomenclature is the orderly system of naming species of living things by giving each species a name made of two parts. The first part of the name recognizes the genus in which the species belongs, and the second part of the name names the species within the genus.