0) Use HTML
1) Use of a reflowable format like HTML, means your format should not be tied to any particular page size.
2) Do not specify margins
3) Use an opf file to specify the TOC.
http://www.idpf.org/oebps/oebps1.2/d...eb12-xhtml.htm
4) Don't embed fonts. Instead just specify font families (serif, sans-serif, monospace, cursive etc)
5) See (0)
General guidelines for how to use HTML:
I really recommend learning to write HTML directly.
a) Use CSS and the class attribute to give your document semantic structure
b) Use percentages and or em to specify lengths. Use logical names to specify font sizes.
c) Split you document up into one file per chapter/section
d) If you insist on using Word, save the HTML file using the save filtered HTML option