In case you're switching from OneNote to Outline here are some useful tips on how to optimise your work with OneNote notebooks in Outline:
    

a) Work with your cloud notebooks from PC OneNote located in OneDrive:

    1. Log in your OneDrive account in Settings > Synchronisation > OneDrive;
    

    
    2. Open your OneDrive notebooks - tap "+" at the top of the notebooks list > Open from OneDrive > select the notebook.
    
    


Another scenario is when you want to work with your notebooks locally. Here is how you can move the local notebooks to Outline:

b) Work with your PC OneNote notebooks locally:

   - Sending the notebook's folder:
  
    1. Find your local notebook's folder on your PC, compress it and upload the .zip file to your iTunes to move it to your iPad:
        

        
    2. How to upload the notebooks to your iPad Outline using iTunes.
                
    3. Open the notebook using "+" > Open from iTunes.


        

    - Sending the notebook's package:

    1. Export your notebook to .onepkg package: FIle > Export > Export current notebook > OneNote package;
        

        
    2. Send your package to your iPad (using your mail client for example) and open it in Outline by taping on the package file > Import with Outline.
        

You can also open the separate sections from your OneNote notebooks.

c) Move the notebook sections to Outline locally:

    1. Export the section by going to FIle > Export > Export current section > OneNote 2010-2013 Section;
    

    
    2. Send this section to your iPad (using your mail client for example);

    3. Open it in Outline by taping on the .one file > Import with Outline; it will be opened in special Inbox for OneNote notebook in Outline.
    


Please note that apart from your Mac, iPad doesn't keep the copies of local notebooks in its system. If you close the local notebook in iPad Outline, it will be lost: make sure you have the backups enabled when working with local notebooks on iPad.