imageNew in OneNote 2010 we transitioned our UI to the new Fluent UI (also called the Ribbon) which was introduced in most apps in Office 2007.  Now for most people you will be able to find all of the commands in the Ribbon without any problem, however our user assistance group created these guides to help you. 

You can find the guides for all of the Office apps and for OneNote:

 

 

Hope this helps!