I am writing a mini-tutorial about how to use docbook to create ebook files.
It may take a month or so to complete. However, I have been doing a braindump about how to create an epub file (and do testing and compose a CSS file).
http://www.imaginaryplanet.net/weblo...s-tips-tricks/
At the moment, Liz Castro's ebook is the best book out there, although she mainly covers it from Adobe Indesign.