Not worth it at all, really. Its for the absolute newbie who's just lazy and doesn't want to go through the forums. Even then, it won't tell you anything of importance...the author will go on giving you 'tips' about, for example, selling to and end user with a query letter, without ever giving any concrete sample.
Its basically a summary (and a very short one at that) of the various concepts in domaining...unless you want to know what domain parking is and what are the names of the various domain parking services (which anybody knows), you're better off spending the $60 at Snapnames.