This book contains a progressive series of techniques for disciplining and strengthening one's mind, leading to more advanced spiritual practices, with a view to bringing about personal improvement and change. I have not yet gone through all of the practices, but the earlier ones introduce meditation techniques, and then lead to more involved practices. The spiritual benefits of these practices can be tremendous, whether or not one completes the whole series.
Which brings me to another point - as Regardie himself acknowledges, 'one year' is ambitious. One can certainly expect to spend longer than a month on many of the exercises, unless already well-versed in meditation techniques. This should not dissuade anyone - a year spent doing just the first exercise twice a day would be a year well spent, in my view.
The book can be considered as a stepping stone to more advanced practices in other books. However, the book by itself provides the opportunity for radical self-change and one need not progress any further than the twelve steps contained within. In fact, one need not proceed through the whole book to achieve some very significant progress; carrying out only the first exercise for a few months is tremendously beneficial to one not already engaged in meditation practices.
I would thoroughly recommend this book to anyone who feels that they could benefit from instilling some discipline in their mind, whether or not they wish to progress to any of Regardie's other, more sophisticated texts. It is rare to find such a straightfoward and effective text in the often 'mystifying' genre of personal growth.