This is not an academically-sourced book, so take everything you read with a grain of salt, because it may have come from a medieval tome, or it might have been made up on the spot. There is no way to tell while reading it.
That said, there is some really good material for working with runes (the section I focused most on, as the section I have the most experience with) and interpreting them, as well as some basic magical practices and theories. I learned quite a bit reading this.
As someone who bases their practice on historical practices if possible, or at least the spirit of historical practices if not possible, I would have preferred a book that focused on actual attested sources. This is still a useful handbook, even if you are not an Anglo-Saxon practitioner (I have a Scandi focus).