I don't know much about the Thoth, but it seems like the sort of system where, if you're planning to write a guide to it, especially an "ultimate" guide to it, you should be a "specialist", so to speak, either very focused on the Thoth, or more generally on Crowley and Thelema/ceremonial magic(k). It's a very intensive area, and not something you can just dabble in (as an author - not going to comment on using the deck, I'd like a copy at some point and am unlikely to manage any really serious study of it...) That the same author has apparently penned an "ultimate" guide to the RWS does not fill me with hope that he'll do the Thoth justice!
Also, " with this incredibly detailed and illustrated guide", "Writing in a convenient format designed for simple reference" - which is it??
Oh my - just searched the Amazon preview (which typically scans the entire text, even sections not available for previewing) for "Crowley", "Thelema" and a couple of other keywords (including Hebrew which, ISTR the Hebrew lettering/gematria is meant to be quite an important part of the deck/system, no?), absolutely 0 results.
http://www.amazon.co.uk/The-Ultimate-Guide-Thoth-Tarot/dp/0738743364 (Hmm, to be fair, I get 0 results for "thoth", too - maybe the search is just broken on this book, but certainly the available-for-preview text doesn't seem to make any reference to Crowley etc, it all seems deeply generic, just referring to/reproducing the images on the Thoth deck (I presume) rather than an RWS or TdM type deck.)
The "10 most important symbols" on each card section seems potentially useful, though - not sure how accurate it is, but it seems to go into quite a bit of detail (this is relating to X classical god, that's a bible reference, those are traditionally associated with Y, etc). On the other hand, all 10 are on one page, so there's no room to go into, say, *why* a crab and a crescent moon means either stubbornness or "clarity of feelings and needs", or how you'd know which is relevant in a given reading. I suppose the book might be handy as a "quick reference" once you've read some rather more in-depth material on the deck?