1. In Reading view you can page through the notebook, expand and collapse sections, and see previous versions of a page.
2. Click Show Authors to see who made changes on the current page. You can do this in edit mode too (View tab).
3. Click Edit in Browser to edit the notebook in the browser; click Open in OneNote to work on it in the OneNote desktop application (requires Microsoft OneNote 2010).
4. In Editing view you can add notes and apply tags to remind you of important items. You can add notes even if someone else is working in the notebook.
5. OneNote Web App has the familiar look and feel of OneNote.
The Home tab has commands for formatting text and checking your spelling. You can make notes look more like formatted documents by applying styles to the text.
Use the Insert tab to add new sections and pages, and tables, pictures, or clip art.
Use the View tab to switch back to view mode, to see who made which changes to the current page (Show Authors command), and to see previous versions of the current page. You can even discard changes by reverting back to a previous version of the page.
OneNote Web App saves your work automatically, so use Undo to get rid of changes you don't want to keep.