We make all your regular narrative paragraphs the same. We add first-line indents, if you did not use them. If you added an extra “return” between paragraphs, we remove those. Extra white lines between paragraphs are discouraged by ebook retailers, as are block-style paragraphs (paragraphs without an indent, with a blank line between each).
For the first paragraph of every Chapter, and the first paragaph after a scene-break, we use flush-left paragraphs (no first-line indent). This is the usual industry standard right now, although some authors prefer something like this: * * *. If this is your preference, simply say so.
As an example of flush-left paragraphs and whitespace for scenebreaks, please see the screenshot of "Jan of Cleveland," in our Mini-FAQ, in the Using Vertical Whitespace for Visual Cues article.