I have ePub documents that won't open using iBooks, how can i get them formatted so that I can use them

Using ubooks myself, couldn't find file, that it would not open.

You could try downloading a program called Calibre. It is very good at converting files between formats. I use it all the time to convert PDF's from work to read on iTunes when I don't want to have to keep zooming in and out to read the actual text.

I know that iBooks will read PDF's but they can get pretty squashed down some times. Especially if the original font was small to begin with. So I run them through Calibre and then email them to my phone and open them in iBooks.

I've just had this issue with a purchased ePub book, from a publisher. I solved it by using Calibre to convert it from ePub to ePub. The resulting file is a few k different in size and the new one copied over OK. I think this issue occured because it originally downloaded as a .zip file and after expanding there was no file type. I added the .epub suffix in order to load it in to Calibre and then converted after the first attempt to load it on the iPad failed.