OneNote notebooks can be linked to CRM record - they are stored in SharePoint.
Notes can be created from within CRM records on the activity wall.
- Enable Server-Based SharePoint Integration
- Configure the entities for which OneNote integration should be enabled (only entities enabled for Document Management can be enabled for OneNote integration)
Check out this video from Microsoft, https://youtu.be/A1ei5DozBKM
Release Introduced Online: