Websites offering free PDFs of Keith Snell books are almost always pirated. Not only is this illegal, but the quality is often terrible (cropped pages, missing pieces, wrong order). Worse, you could download malware. Support the composer and publisher so they keep producing quality educational music.
The series is designed to provide a "well-balanced and complete curriculum" by dividing repertoire into specific historical and stylistic categories at each level. Neil A Kjos Music Company Baroque & Classical Volumes: keith snell piano repertoire pdf
Searching for is a sign that you are serious about improving your piano playing. You want structure, quality music, and a proven path to excellence. That is admirable. Websites offering free PDFs of Keith Snell books