If you have the CNotes module published your users will be able to write notes and view the notes that they wrote on any page. Now on each page they can see only the notes that they wrote there. If you want to make their live easier you can provide them with a link to all their notes. To do so you have to create a new menu link. In the Joomla backend go to Menus -> Your-menu-> "Add new menu item" . In the "menu item type" field click on Select and then click on "User notes". (make this link available only to user registered users). Now when you click on the link you should see screen similar to this one (provided that you've written any notes)

Clicking on the delete button will delete the note. Clicking on the title will send the user to the page where he wrote the note. And clicking on the title will bring them to a screen where they can edit their note: