Hi there! Good questions.

I use Calibre (on my laptop, haven't transfered any books to my PE yet), and my husband has a Kindle, so we buy Kindle books. Before you can convert them in Calibre -- an easy and effective process -- you have to strip the DRM from Kindle books, which is ethically questionable (we figure we own the books so we do it ) and not super easy. Once you have the right programs and information, stripping the DRM takes a few steps for each book. Then you can add the books to your Calibre library and convert them all at once. (I'm not sure exactly how many titles you can convert at a time.)

In addition to .mobi format (which Kindle can read), Calibre converts .pdf, .epub, .rtf, .txt and a bunch of other formats. So if you have a Word document you want to read as a .pdf or .epub (for instance) you can do it. However, you'd have to convert it on your PC and transfer it over to your EE before you leave .

For help with Calibre and hints on stripping DRM, go to www.mobileread.com, as Sarah suggested.

Good luck! Let us know what you decide.