I AM PLAYING WITH LaTeX, an e-publishing tool that looks like it could fulfill many ebook publishing needs I've encountered. The handy thing is that you can then convert a LaTeX book into HTML.
The Irish LaTeX community is vibrant. I've discovered people willing to share specialised macros as well as packages developed in the Share-and-Share-Alike spirit. But beyond the packages, I want to find someone who is developing an HTML5 front end editor so I can use LaTeX as a backend. An attractive HTML5-based ebook creation tool would hold its own against iBook Creator.
I learned about LaTeX, one of a number of dialects of TeX, from John Jennings. It is particularly suited to the production of long articles and books, since it has facilities for the automatic numbering of chapters, sections, theorems, and equations. It also cross-references elegantly. It is the most suitable version of LaTeX for beginners to use.
Leslie Lamport -- LaTeX User's Guide and Reference Manual.
Michel Goossens, Frank Mittelbach and Alexander Samarin -- The LaTeX Companion.