Could you suggest a better one for the newbie? I've yet to run across a copy of
Thelema for Dummies.
Even though they are a bit lacking in some areas I would be more inclined to direct a complete newbie towards the introductory books written by Rodney Orpheus or Gerald del Campo.
Gunther's book is a different kettle of fish in my opinion. It's not a general introduction to Thelema. It's a highly specific work focusing on the path of initiation
within a Thelemic framework. Not everyone who gets interested in Thelema goes down the initiatory road. Some people go no further than accepting the Book of the Law and trying to live their lives according to their understanding of the text. There's nothing that says they have to start doing a graded course in Yoga, Ceremonial Magick, or anything like that.
Of course many people do want to dive in at the deep end, and Gunther's book is a great resource for the individuals drawn in that direction. But presenting Gunther's book as a general intro could be a bit misleading for some people because taken on it's own it appears to suggest that the path of initiation is a necessary requirement for anyone who wants to get involved in Thelema, and I don't think this is the case at all.
Crowley says something to this effect in the very first chapter of Liber Aleph.
It is not every Man who is called to the sublime Task of the A∴A∴, wherein he must master thoroughly every Detail of the Great Work, so that he may in due Season accomplish it not only for himself, but for all who are bound unto him. There are very many for whom in their present Incarnations this Great Work may be impossible; since their appointed Work may be in Satisfaction of some Magical Debt, or in Adjustment of some Balance, or in Fulfilment of some Defect. As is written: Suum Cuique.