You'll need to be more specific about what type of documents you want to work with and where they are currently stored, or if you're going to create them from scratch.
In general, you can find an app (usually many apps) to edit most document types. Depending on the app you can either copy the documents directly to and from the computer with a cable or wi-fi, or you can use a cloud service like iCloud, DropBox or Box.com to copy the files.