I began writing ebooks over the summer. To date, I have written four educational/reference titles around a theme -- "In 30 Minutes". The idea is to let newbies quickly understand a mildly complex topic. The most recent title is The $10 Small Business Website In 30 Minutes (1).
Not only do these books contain lots of screenshots and detailed TOCs, I also publish them in multiple formats -- .mobi, ePub, PDF, and PDF for paperback.
Unfortunately, I discovered that the most popular writing tools -- Microsoft Word, Google Docs, and Apple Pages, are not up to the task of creating ebook files across all of the platforms. Even if they can export to a certain format, there are limitations that force additional production and conversion steps. I also encountered the problem of forked masters, when I had to use different tools for exporting/converting to special formats.
Currently, I am using Google Docs for composition and collaboration with my copy editor. I then copy and paste the text into Scrivener (2), which is the most powerful writing and publishing tool I have ever used. It exports to .mobi, ePub, PDF, and print book PDF. Like TFA, I use Kindle Previewer to test the .mobi files. The ePub files need some mild HTML cleanup, which I do in Sigil (3).
1. http://10dollarsmallbusinesswebsite.com/