I've tried reading books off an Ipod Touch, though it wasn't the kindle application, but all I know is that it annoyed my eyes. The Kindle is just like reading with a book, no glare in the sunlight and having a book light is handy but not necessary as long as you have the light you would need to read any regular hard copy book. You don't
need a book cover, but I would recommend one, I purchased the one I have because I'm a "butter-fingered" person and will own up to already dropping this beloved object. I don't know if it would have survived without the cover, plus I like to drop it in my over-sized purse and who knows what kind of sharp objects lie at the bottom of that thing :P
The cover I bought in brown
Amazon.com: Kindle Lighted Leather Cover, Black... It makes it a little bulkier, but again if you have a tendency to drop expensive electronics I will definitely recommend it