Jason Boog at GalleyCat has collected links to the publishing and marketing guidelines for most of the major self-publishing outlets in his post “Free eBook Formatting & Marketing Guides for Writers.”
The post includes links to Smashwords, Amazon Kindle, Barnes & Noble NOOK, Kobo, Apple iBooks, and Calibre in one place. If you are self-publishing or creating eBooks for someone who is, this is a nice resource.
Are these guidelines helpful to you? Is there any information that is missing? What other guidelines to you need or use?