I would suggest that this is one of the best books ever on guitar chords in popular music. I found it to be a better book than 'Chord Master' from the point of view of a guitarist looking for ideas and practical chords though you might eventually get that or any other of Rookby's books as they are all quality works.
I wouldn't agree that it is not for beginners; it might not have guitar tuition as it's main purpose but certainly provides plenty of chords and, particularly important, chord progressions for all levels of popular guitar playing. Motivated beginners can easily find a few at a time to play around with. More experienced players will find both chords and theory to fill in their knowledge.
You can take or leave the theoretical coverage rather than the actual chords, perhaps come back to it as curiousity demands - what counts with guitar is what you can do, even if it is just a few chords played well, and the many diagrams and progressions are pretty much self-explanatory. Likewise, the song-writing content could be considered more or less important depending on your emphasis. It might make a guitarist out of a song-writer or vice versa.
In any event, if you want to play popular songs on guitar, I would recommend this quality book as a very good start and one to refer to well beyond that, wherever you go eventually.