Some news on the EPUB creation front:
Google Docs just enabled a feature to export as EPUB! To use it, simply open the doc and look under File > Download as > EPUB Publication.
This is a handy and very easy method to create an ebook. However, the consistency and quality isn’t good. The markup it creates is down right bizarre with tons of unnecessary <span> tags and strange CSS. It also does not create a cover. In theory you could open this Google Doc EPUB with Sigil and do some polishing up, but given how unnecessarily complex the markup is, it would be more work than starting fresh.