First up is an ebook overview for people who haven't explored them yet. Yeah, I know most of the people who pop in here are tech savvy, but if you know someone who isn't, point them to this video.
GreenerBusiness 13: Ebook Readers
Books - eBook reader for iPhone/iPod Touch
RasterBook demo - read eBooks on iPhone
iPod touch as a book reader
This one is sideways and in German, but it shows a different and longer list of settings:
And this is a tutorial that actually taught me something:
"How To" Create a FREE eBook (Using Gmail) Wolf pack
Update: Another video.
iPhone and Ebooks: A Flirtation Continued