There are buttons below the cover art for each work. If recordings or sample pages are available, the left two buttons (respectively) will appear in color. Clicking the first button will expand an audio player that will allow you to play tracks from the work in question. Clicking the second button will open a PDF viewer within the current window that will display sample pages from the work. If no recordings or sample pages are available, those buttons will appear gray.
In addition, many of these works have partial or complete Score Browser videos on YouTube, which allow you to follow along in the score while the recording is playing. You can view these videos by clicking the third button below the cover art when it appears in color. A video player will open within the current window that will allow you to view the video without navigating away from the site.