The link on Make is to an older, unrevised version of the Sony PDF creation guide. A link to the revised version can be found here:
http://en.wikipedia.org/wiki/Sony_Reader
Actually, the only difference that I have remarked is that the revised version gives a corrected size for documents formatted to fit the Reader display: 3.47 by 4.54 inches, rather than 3.57 by 4.82 inches. However, this is not trivial--the former works out right, the latter doesn't.
It's also important to realize that it's primarily a guide to
creating PDFs for the Reader, not to reformatting existing PDFs. These are different things. Reformatting an existing PDF is quite problematic, and not what this guide is mainly about.