The workflow part is relatively easy.
I have just finished creating two books in Pages, exporting them to ePub format.
Double click on the exported file, and it is viewed in iBooks - or "previewed" if you like.
You can also download the Kindle Previewer interface, which converts it to a mobi format, and previews it.
If you have become an iBooks Producer - you can also download a neat previewer from there that interactively allows you to proview you book on any Apple device, and reflects the changes immediatly.
Apple's app to help you develop and test EPUBs.
This is a very useful piece of software. Simple as ABC to use.
- Delivery for iBooks. You can send your epaub directly to the itunesconnect portal that you log into, als o your cover page, and promotional images if you want them.
- Delivery for Kindle. Same thing, upload using the kdp.amason.com interface when you login.
If it looks good on your iBooks it looks good on yoru Kindle.
Now, as for Fixed Layout. It's not worth the drama. Really. ePub 3 references are delving into it, but as each device is different - it's always going to be difficult.
My only solution is to use iBooks Author, and lots of images. It gets close, and if you LIMIT your book to one size device, you may be able to do it.
But the only way I have found to approach it is to use images of things that you don't want to ... flow, and you must add them "in line with text", not fixed on page. So they follow a text anchor you put them with.
I have no doubt that I will be corrected on a lot of this, but it works for me. I am writing, and producing books that when it comes to publishing, don't tke long at all. I don'twant to get bogged down in days of fiddling to try and master some arcane conversion process.
I have text book in print form that I'd love to convert to ePub, but it's all tables and graphs and Q&A type things, and although I started - it's just too difficult to convert to ePub.
I'm now doing a complete re-think on that one, to see if I can offer it in a suitable format. Redesign it as it were.