Regardless of the title, "The Core Workout..." is for everyone, in particular for beginners who want a solid and sensible grounding in form and technique. The reason for the title's "dedication" is that the authors' ultimate focus is that your final workout routine should be tailored to support the demands of your chosen primary sports routine, be it skiing, golfing, etc. However, this is just one late chapter and can be ignored if this is not your focus.
Swiss balls can be used for a lot of things. The book puts the swiss ball to use in the service of 'core workout', the idea that strengthening lower-lying abdominal muscles has a number of beneficial effects, including better posture, decreasing back pain risks, and generally providing a functional workout. A 'core workout' is not restricted to working core muscles - their special use is just integrated into exercises covering legs, upper body, back, arms etc. Furthermore, it is not 'strength training' per se, although the final chapter is devoted to that. A core workout will tax balance and stamina more than explosive strength.
The book is laid out simply and helpfully with a nice big readable font and good photos. The progression through the book is excellent: You start out by reading about basic techniques and principles, which is really the reason you want to buy this book rather than just google some ball exercises. "Form is everything", the authours keep stressing and they back it up with explaining (and constantly referring to) said form in an admirable fashion. The explanations of these ideas really help you understand what it is you're doing and why when doing an exercise - something I often find missing in other such books. The book then takes you through some checks to make sure you understand and are capable of using the techniques and the provide a basic programme. Finally, you have - as in every such book - an exercise library with which to supplement the basic programme. While the additional exercises seem okay - and feature some helpful suggestions on how to making them easier/harder - they are not particularly well structured, so there's not much advantage here over just searching google or youtube.
If you're looking for a good starter's guide to ball workout, it's definitely recommended, even if you have a different focus from the authours', as it provides some genuine insight in to what might be termed 'basic ball dynamics' and a useful introduction to the concept of 'core muscles' without needlessly confusing the reader with (pseudo-)science. Furthermore it IS an actual book, not just an random collection of exercises with a hastily written introduction, leaving the reader to figure out how to proceed.