Inasmuch as the W3C Japanese Language Task Force’s “Requirements for Japanese Text Layout” Note was released last month, my article about it, “Designing Japanese documents“, is now available from tcworld magazine.
The Note “describes requirements for general Japanese layout realized with technologies like CSS, SVG and XSL-FO”. It covers page design conventions as well as how to layout lines. Naturally it covers Japanese-specific details such as vertical text, mixing Japanese and Latin text, ruby (small-sized, supplementary text), warichu (inline cutting notes), tate-chu-yoko (horizontal in vertical setting), and furiwake (multiple phrases or sentences in in the middle of a line).
The article provides an overview of the Note (and was good practice for the in-depth analysis that needs to be done for one of the XSL 2.0 requirements), but if you want all the details, then you need the Note (and if you really want all the details, then you also need JIS X 4051, and possibly assistance in reading it).