Here is a new ebook I've made available on the wiki, in ePub format. http://wiki.scribus.net/canvas/Books#Scribus:_a_Reference
As I add more chapters I will update the file. As you can see, this is a different approach than most if not all other Scribus books out there. Licensing is CC by SA (3.0) and GPLv2. Let me know about any errors or important omissions. Greg
