1. A method for supplying hierarchical supplementary information related to printed books in a portal comprising the steps of: establishing a portal of supplementary information related to printed books, said supplementary information stored in hypermedia documents retrievable through said portal; distributing to a user base a plurality of different printed books; associating each different printed book with a common uniform address, each said common address referencing a corresponding first hypermedia document in said portal, said first hypermedia document comprising links to secondary hypermedia documents, said links corresponding to different ones of user classes; providing a kiosk for interacting with said portal; receiving from a user in said user base through said kiosk a user-specified common address corresponding to one of said printed books; responsive to receiving said user-specified common address, displaying through said kiosk in said portal a first hypermedia document corresponding to said user-specified common address; identifying in said first hypermedia document corresponding to said user-specified common address a user class associated with said user; and, responsive to identifying said associated user class, displaying through said kiosk one of said secondary hypermedia documents, said secondary hypermedia documents having supplementary information pertaining to said books associated with said user-specified common address, said supplementary information being consonant with said associated user class.