SharePoint team site comes with a Notebook link in the Quick
Launch. It opens the Online version of OneNote, Microsoft's
note-taking tool that is part of the Office package.
OneNote Online works well in the browser, and by having
it in SharePoint you can easily share it with other team
members. The OneNote notebooks are stored in each team site's
Site Assets library.
In the demo below Peter Kalmstrom, CEO and Systems Designer
of kalmstrom.com Business Solutions, gives an introduction
to OneNote. He opens OneNote Online via the Notebook link
in the Quick Launch and shows the various options, and he
also shows how to create new notebooks.
If you don't want users to have access to OneNote, you can
remove the Quick Launch link and existing notebooks in the
Site Assets library, but if you want to remove OneNote from
the default options when you create a new document in a
library, you need to change the content type of that library.