To upload a Word file from the computer when you are logged into iCloud, just drag the file into the browser window or use the Upload Document option on the Settings menu. You can then download the files as Word documents from the MacBook Pro using a Web browser, as explained on an Apple support page. Once you set up an account, you can save the files you have edited in the iPad’s Pages app to iCloud. To use iCloud, you need to set it up on your computer and iPad instructions are on the service’s setup page. Since Apple has a hand in all the components in play here, the company’s own iCloud service might be the easiest option (but it is not the only one). Using an online cloud storage service is one way to share files between Mac and iPad.