Are you asking about the Complete Idiot's Rock Guitar book or the one on "regular" guitar that's coming out this fall (I was told October 5, but I can't verify that date as of now)?
Both of these books start out by assuming that the reader has never picked up a guitar before. And both approach learning the way I do here at Guitar Noise - I want to get people playing. You will get some basic overview of time signatures, note reading, tablature reading and such, but that's over with in the first four or five chapters. While some of the same material is covered in both the books and podcasts, it's not a rehash of any of the podcast material. You do get some overlap - can't be helped with tutorial books. For example, both books and the podcasts discuss the importance (and ease) with which one can add slurs like hammer-ons, pull-off, slides and bends to strumming. But while the podcasts do so more in a manner of exercises, the guitar book this fall will use Gallows Pole (as well as other songs) as a way to demonstrate this technique.
If you'd like, I can send you what the Table of Contents is (hopefully) going to be like so you can make a better decision for yourself.
Hope this helps.