I often add lyrics (not documents) as textfile via copy and paste from Notepad (which comes with the iPad) or GoodReader.
The problem is that I can't edit neither the very first nor the very last two or three lines of the text. It scrolls up (upper lines) or down whenever the keyboard appears.
I help myself for the moment by adding a series of "return" at the very beginning and the end to avoid this scrolling away, but that way isn't satisfying for me.