• A computer with iTunes loaded
  OR
• iCloud, and "Documents and Data" ON (for iWork files)
  OR
• iCloud Drive

Documents in the Cloud

To use Documents in the Cloud, you will need to have Keynote, Numbers, and/or Pages on your iOS device, but also on your Mac, because iCloud only works for iWork documents, and does not work with, for example, Microsoft Office. If you do use iWork, then you will first need to go to http://icloud.com/#iwork on your Mac. Then click on the gear icon in the upper right.

Now all that you need to do is let it upload, then walk over to your iOS device and open one of the iWork apps.

iTunes File Sharing
Keynote, Numbers and Pages are capable of reading Office files, but Office files cannot be copied to iOS using iCloud. If you don't have iWork or iCloud, you can sync documents through iTunes File Sharing. To do this, you will need to open iTunes and locate the name of your device under the "DEVICES" menu on the left.

iTunes 11 users may need to reveal the sidebar first - iTunes 11: Show Sidebar and Status Bar. iTunes 12 users must click on the device icon and click "Apps" from the sidebar that appears, then scroll down to the "File Sharing" section. See Adjusting to iTunes 12. The below two steps are for iTunes 11 and earlier users.

After selecting your device name, a "Summary" tab will open at the top of the screen. Instead of the summary tab, we want the "Apps" tab, which is located at the top, close to "Summary."

After clicking on "Apps," scroll down until you see a header "File Sharing." Under this header, you will see a list of apps that are compatible with File Sharing. Locate Keynote, Numbers or Pages from this menu, and then click on "Add" to choose a file and share it with your iOS device. If you have another app that can read Office docs, such as DocumentsToGo, this will work for those as well.