Is the layout for your eBook going to be complex or is it a simple layout?
One program I suggest you install is Adobe Digital Editions 2.0. I know it's an old version, but if your eBooks looks good there, it will most likely look good in a lot of other programs or Readers.
https://adobe-digital-editions.softw...r.com/versions
Some quick tips.
- Do not set an overall Left/Right margin. Leave it at 0.
- Do not set a line height.
- Do not set a font size for the main body text.
- Do not have so much wasted space for chapter headers.
- Do not have paragraph spaces except where needed such as section breaks and offset text.
- When having offset text, do not make it a smaller font size then the main body text.
- Do not use embedded fonts unless needed and not for the main text.
- Do not set the main text to any specific font or font type.
- Do use indents and set them between 1.2em and 1.5em (I prefer 1.2em).
- At the beginning of the chapter and section breaks, the first line of the first paragraph should not be indented.