My process is very simple. They are way more technical than me. I start off by entering everything into Word and get the text nicely formatted, then I work from that to create the PDF, epub, and Kindle versions.
The ebooks I put out have definitely improved since I began the site though.
My abilities only run as far as HTML and CSS - although I did just start learning programming recently (so I have a fallback career in my fast approaching old age!)