I think you will be quite pleased with the Nexus 7 as an e-reader. You have the native e-reader that comes with the tablet which will allow you to easily purchase books from Google Play or if you prefer to read material from other sources, you can choose Apps that will display ePub, Mobi, and PDF, to name a few. You choice of E-reader Apps will allow you to turn pages by sliding or that actually emulate page turning and even show bookshelves with the book cover. I should remind you that, as with any color tablet, you will not be able to read in direct sunlight.
Hope you decide on the Nexus 7 and join the community.