The book contains reference details of everything you could possibly want to know about I18N (Internationalization) and L10N (localization) in the context of Microsoft Windows (MFC and .NET) development. It addresses culture and language rendering issues very well. It tells you everything you need to do, but nothing about how to do it i.e. it does not address implementation at all. Also the book is slanted towards development from scratch. It does not address the process of retro-fitting an application for I18N/L10N.
The book is worth its price tag for the sheer volume of relevant information and the breadth and depth of coverage, but don't buy it expecting to find programming recipes, sample code or gotchas.