New ipad iphone buyer here needs help on file download/transfer.

My wife and I are dipping our toes into the Apple world for the first time. Me with iphone 5, her with ipad 4. Both of us are long time computer users.

Here is the problem. She is legally blind and has a specific need to down load special audio files from the Library of Congress onto a USB Memey Stick which she then uses to play the special Audio Books on the Library of Congress reader for the blind. This process works well on the PC but I cannot work out how to do this on the ipad.

Has anyone any experience on downloading files and transfering to a usb device. I note that Apple has a lightning 4 Camera USB cable and wondered if a gender change adaptor would work. Also would like advice on an App to help with download file copy to usb.

Hope some of this community has the know how.

Brian