A new book, "Passi e Valli in Bicicletta, Valle d'Aosta" written by Franco Cuaz and Stefano Marta has been published by Italian publisher Ediciclo (http://www.ediciclo.it/). The book is targeted at the disciples of climbing, "grimpeurs", featuring 57 climbs in the beautiful Valle d' Aosta, a region located in the northwest corner of Italy. This is the most recent publication in a series of books focused on climbs, other examples:
PASSI E VALLI IN BICICLETTA PREALPI VENETE 3
PASSI E VALLI IN BICICLETTA PREALPI VENETE 2
PASSI E VALLI IN BICICLETTA LIGURIA 2 IL PONENTE
The complete list of books dedicated to climbing can be seen here: http://www.ediciclo.it/index.php?qr=salite&pagid=prod_list&cat_id=5
Ediciclo is also a good source for book detailing routes of all types, in all parts of Italy.
The book uses a ranking system to classify the difficulty of the climbs based upon a range from 1 to 5. There are no climbs ranked lower than a difficulty of 3; 22 climbs are longer than 17 Km; 32 climbs reach more than 1,000 meters in altitude.