Let me just start with the fact that I've not gone through the book fully yet. So don't rely fully on my review.
I am also from Norway so Fluent in Norwegian, (English) and have a good understanding of New Norse, Swedish and Danish.
The reason I want to learn Old Norse is because I found I could understand a decent amount of words when coming across some texts on the net and figured it would be good to learn the language my main language is built on and also understand a little of Faroese and Icelandic as well to cover the Nordic (minus Finnish) languages.
I'm going through the book and trying to learn on my own and in my spare time and whilst traveling to work.
In the beginning of the book they go through how certain letters are pronounced when next to certain letters and how they are pronounced when next to other letters (if that makes any sense). What I find unhelpful with it is that it uses sounds of French words. I don't speak French and have little idea of how the word examples are pronounced so I may very well be getting the wrong sounds. I decided on using a more Norwegian/New Norse sound to these letters or at least the closest to the letter they resemble in the Norwegian alphabet. If you are to speak the language you learn, being able to pronounce it is important, and especially when there are letters and sounds that can change a word that looks almost the same so much.
Other than that the book does well to describe how sentences are constructed, giving sentences in Old Norse, it's translation and the meaning of it in English. All in all it's a good book to learn the grammar of Old Norse and I would recommend it to anyone who'd like to learn.
However, like I said at the top, at the time of writing this I have not finished the book.