Techradar posted an article on OneNote for Windows 8
When you select a page and start looking at content or adding information, the notebook panes slide off to the left to leave more space on screen for your notes.OneNote for Windows 8 is Microsoft's first serious Metro application
Tap on the notebook name to get them back on screen, or open both the notebook lists and see other handy commands like forcing a notebook to sync or copying a link to your notebook by swiping up from the bottom of the screen to open the App Bar.
That's a standard Windows 8 gesture – if you don't have a touch screen, it's right click on a mouse, but Microsoft is keen to push OneNote for Windows 8 as a touch app.
