Priesthood and the administering of Sacraments

I was wondering if anyone had any documents or respectable references regarding the evolution of the priesthood and the administering of sacraments (including the origin of the sacrament of chrismation). I have always wondered why the apostles suddenly decided to "lay hands"....where did this come from? Christ never mentioned anything about "laying hands." It seems that the lay people in the early church had received the Holy Spirit along with exercising the sacraments such as the breaking of bread and that it was not until there was an issue regarding the Hellenists and the Jews regarding the Eucharist that they decided to consecrate the administering of communion to those who were chosen to have hands "laid on." The confusion is, it already said that these men were full of the Holy Spirit. I am trying to understand how all this came about......