I am in total love with my Nook ereaders, I have the Nook wifi and I also have the tablet ereader, Nook Color. Both are fabulous and I could rave all day about them. What I do not love is the price of the ereader covers. They are pretty basic to make and I can make them for like $3 in supplies/fabric. Like most sewing projects I undertake I just winged them.
The one I just finished, I made with the intention of giving to Miranda, but we all know what is said about intentions. This one is fine, but I want to make another with a few less imperfections. Also, the fabric color scheme is much more my style than Miranda's! I have a more colorful and fun fabric set aside for Mir's now.
The outside, I like to use a more durable cotton fabric like an upholstery material. I also use a stiff interface inside to help protect the Nook from any dings and drops. You can always find decent size remnants too. :)

The inside, my nook is in the reading position. You can bend the cover back just like a paperback book.

I left an opening in the bottom holder so that the speakers and charging area are accessible.

I am not really a fan of the large side pocket but you can store the Nook in the pocket when you are not reading. You can really store anything in here and it is 'padded' (stiff interface) so the face is protected.