In many schools, independent silent reading of self-selected books is used to promote reading. However, self-selection may be insufficient to counter negative reading experiences, particularly when students choose books not attuned to their reading level and interest. Two studies experimentally tested whether personalized expert guidance when selecting books could prevent a reading attitude decline. Study 1 focused on readers in prevocational secondary education (Grades 7 and 8; N = 136). Study 2 included younger readers from primary education (Grades 4-6, N = 99). Students in the experimental condition met with a librarian to discuss book choices every two weeks for three months. In both studies, the intervention stabilized the reading attitude decline, although, in Study 1, only for more advanced readers. In Study 2, reading comprehension of the most proficient readers also improved. This indicates that guidance in selecting books can preserve students' reading attitude and increase reading proficiency growth.