We're very excited the coming week will see a major piece of research into digital publishing released, a project some of us have been working on for several months. We'll cover it here, and on Twitter, when it launches.
For guidance on digital publishing, see the EBW Knowledge Base, a Creative-Commons-licensed collection of advice and practical how-tos from Arthur Attwell's company Electric Book Works. It includes items on creating PDF and epub ebooks, digital rights management, and self and small-scale ebook distribution.