Turns out to be a bit more complicated than I thought. I should have realised it is almost as technical - or maybe more so - than producing a print version. There are a range of things to consider, such as the systems and readers the work will be available on. It appears there are several different operating systems in use and each has its own coding process. Plus, it isn't as simple as just copy/paste into the required format.
To be successful, it has to have the same appearance as a printed book - so pages have to be formed, bookmarked and formatted. In short, it is the same process as is required to produce the Galleys for a printed book - but with the added twist that, because it will appear on a screen, you have to be able to scroll it and go to a page, chapter or section on command. It's been quite a learning curve. Guess I'll now have to buy an e-reader so I can actually get used to this technological stuff myself.
Cutting to the chase - both a friend and I have books in preparation for the New Zealand based company - ePublishing for Success. It's proving to be very interesting!