From An Alphabetical Book About Nokia Pure:
Body copy leading
9pt on 11pt (2pt leading)
36pt on 40pt (optical line spacing), 36pt on 44pt
The first paragraph does not have an indentation. In successive paragraphs the first line is indented.
Full line break
Instead of indenting, use a full line break to separate paragraphs of texts.
Efficient reading depends on a comfortable line length between 40 and 75 characters.
We recommend using hanging punctuation, or exdentation, in which the punctuation or bullet points are set in the margin so as not to disrupt the text alignment.