On her website, author Amythyst Raine describes her book in the following terms - "With "The Gray Witch's Grimoire" you can empower yourself through ancient mysteries, secret rites, and magickal spells that leave the world of the mundane behind and nurture the wise-woman in us all."
That 'wise woman' comment is important to pick up on - not all of us gender identify in this way, but this is very much the book for women who are deeply involved with the magical and divine feminine. One of the things reviewers have commented on repeatedly is that this is a gendered book, it's written by a woman, for women, based on a very feminine experience of witchcraft. That doesn't mean its of no use for a male reader, as this amazon review demonstrates
There's an interview with Amythyst in 'The Spellery' which you can pick up a bit of on the author's website - http://www.ladyamythyst.com/