The #1 formatting mistake we see authors making when they prepare their file for ePUB conversion is using the tab key or spacebar to indent paragraphs in a Word document. If you want your eBook to be as pretty as can be, AVOID the tab key and spacebar for paragraph indents. Instead, use the paragraphs settings in the formatting palette in Word to set indents to the first line of each paragraph. This will make ePub conversion a snap!
-Chris R. at BookBaby