The purpose of this book has been to demonstrate that illustrated vernacular manuscripts provided young Florentines with knowledge to help them succeed in their lives. The knowledge offered by these manuscripts could be used to establish good relationships with others, to take civic responsibility and contribute to the common good, to restrain lustful impulses, to prosper in business, and to understand the physical world and the workings of nature. I have focused on manuscripts of a select group of works: the Fior di virtù, the Esopo volgarizzato per uno da Siena, the Sfera by Goro Dati, and a few libri d’abbaco. The reason for choosing these works is that, in addition to their extensive illustrative cycles and their wide diffusion, there is evidence that they were read by the young.