This is a very cool book, but it is not a field guide. It is a very well organized and illustrated scientific key. It has one purpose and one purpose only. Determine the genus (the level of identification above species) of the spider you have captured, and provide references to publications that discuss the species in that genus. To utilize this book you should have or be prepared to purchase a dissecting microscope. In many cases to complete a rigorous identification you will need to count setae (hairs), examine fangs or dissect and examine the gonads of the specimen. It is also important to realize that some identifications require killing the spider. One may attempt to skip steps in the key requiring dissection, but that of course introduces complexity and reduces the certainty of your identifications. In some cases dissection may simply be required. Another thing to note is that this manual is for use in the laboratory, or other environment whe you can manipulate the specimen. It is basically useless for field identification.
If you are disappointed by the above description and were hoping to identify live spiders kindly left in your back yard, the unfortunate reality is that spiders are complex little critters and identification beyond the family level is painstaking. The authors cannot be faulted for that, as it is simply a fact of life.
This is clearly a good book for the scientist or graduate student. It is also a good book for someone like me who has a biology degree, is not working in the field, but has been continually vexed by the lack of specificity in field guides. It may even be a good book to give to an aspiring high-schooler who has a genuine interest in biology, particularly spiders or insects, but ONLY if you also give them a stereo dissecting microscope too. This book is not for children below high school, and not for children or adults who have only a casual interest in spiders.