Unless you use third-party apps, the most direct way to add documents to the iPad or iPhone directly is to use the File Sharing capability built into iTunes. If you want, you could use many best file sharing iphone apps from itunes.
You can also use File Sharing to copy documents from the iPad or iPhone to a PC or Mac. This is useful both for documents you’ve created on the device (for example, by using the iWork applications on the iPad) and for documents that you’re using the iPad or iPhone to transfer from one computer to another.
To transfer documents by using File Sharing, follow these steps:
1. Connect the iPad or iPhone to the computer as usual.
2. If the computer doesn’t automatically launch or activate iTunes, launch or activate iTunes yourself.
3. In the Source list, click the entry for the iPad or iPhone to display its control screens.
4. Click the Apps tab to display its contents.
5. Scroll down to the file Sharing area.
6. In the Apps list, click the app to which you want t to transfer the files. The list of files for that app appears in the Documents pane to the right.
7. To add documents to the app, follow these steps:
a. Click the Add button to disply the iTunes dialog box (on Windows) or the Choose A File: iTunes dialog box (on the Mac).
b. Navigate to and select the document or documents you want to add.
c. Click the OK button (on Windows) or the Choose button (on the Mac).
8. To copy documents from the app to the computer, follow these steps:
a. Click the Save To button to display the iTunes dialog box (on Windows) or the Choose A File: iTunes dialog box (on the Mac).
b. Navigate to the folder in which you want to save the document.
c. Click the Select Folder button (on Windows) or the Choose button (on the Mac).
File transfers generally run pretty quickly, as USB 2.0 can handle up to 480 megabits per second (Mbps)–but if you’re transferring many large files, it’ll take a while. And if you’re using a USB 1.x port, its 12 Mbps limit will make things much slower.