In addition to adding more thorough and long documents, you can also add notes to the Site View page to jot down anything short but relevant you think should be seen or remembered in connection to the specific site.
To add a note to a site, go to the site view by clicking on the site name in the list - the Notes section is in the top right corner.
To add a note, click on the "Add" button in the top right corner, and when you're done typing in the note, click "Add" again and the note will show up in the note area along with the date and who wrote it.
And that's how easy it is!
Here's the next article.