"A Modern Method for Guitar" takes a music-only approach to teaching guitar. Many cite this book as the best way for budding guitarists to learn to leave the world of tabulation and join the rest of the musical world. As other reviewers have noted, this book is packed with musical notation and has an extremely high learning curve.
I have to admit that this book works very well as a guide to sight reading. You'll learn how to find the right note as you work through these exercises, and the more you expose yourself to this material, the easier it will become. If your sole intent is to learn how to sight read, I would recommend using this book.
However, this book fails in every other aspect. Chord structure is barely taught at all, and some of the fingerings are nigh unto impossible. The Chordal Etudes start out as difficult, and quickly become extremely confusing, as the authors decide to throw unusual chords and odd harmonies into the mix. I had to run to my piano from time to time just to make sure I was hitting the right notes.
The authors also seem incapable of teaching basic scales without throwing in chromatic elements to throw you for a loop. It doesn't sound bad once you get it; however, it is not easy to learn the shape of the scale when every single scale exercise throws in a few accidental notes to keep you on your toes. The Reading Studies are uninspired at best, and the melodies of the actual songs feel like they were written by machines.
There are better books out there. The learner would do much better spending money on the Fundamental Changes series to learn chord formation, basic music theory, and even standard musical notation. Once you've learned a few basic chords, you're much better off grabbing a collection of folk songs and playing around than trying to wrap your fingers around the chords in this book. I recommend playing what you enjoy, rather than trusting that the folks at Berklee know what is best for you.
I'm not certain who this book was written for. Beginners should stay away. Intermediate players will grow frustrated by the end of the first book. Advanced players might stand a change - but, then again, an advanced player probably has better things to play than these uninspiring, flat compositions.