At the age of twenty, Naudé published his first book "Le Marfore ou Discours Contre les Lisbelles". The work would bring him to the attention of Henri de Mesme, "président à mortier" of the Paris Parlement. Mesme offered Naudé the job of librarian to his personal collection. Mesmes had a large library for the period (about 8,000 volumes) and it was open to scholars who had the appropriate references. Naudé's service in Mesme's library would give him experience which he would use later to write the book "Advice on Establishing a Library". Naudé wrote "Advice" for Mesme as a guide for building and maintaining his library. In 1629 he became librarian to Cardinal Guidi di Bagno at Rome, and on Bagni's death in 1641 librarian to Cardinal Francesco Barberini.