This book offers a very good complement to the instruction manual supplied with the case. For attention, especially if like me you are a beginner, it will provide absolutely no you reading it. The manual, quite technical, focuses on the "how to" book while Luc Vincent explains "why do this or that" in a relatively simple and clear style. Apart from its target of talk about the 500D, it speaks also of course basic photography concepts which can be very instructive as your base level (rather low for me).
Readable and well-illustrated above, which probably explains its slightly higher price.