Complex sentence: The sacristy leads to the "Scoletta" or "Scuola Piccola della Nazione Tedesca": a hall with a series of canvases of the the "Life of the Virgin".
Split into simpler sentences: The sacristy leads to the "Scuoletta" or "Scuola Piccola della Nazione Tedesca". That hall has a series of canvases of the the "Life of the Virgin".