This is a useful volume, with beautiful pictures of a moderate diversity of the Northeastern fungi. However, after reading some of the other reviews here I feel compelled to say that this book doesn't hold a candle to David Arora's 'Mushrooms Demystified,' which has vastly superior keys and species coverage, even for mushroom ID in the northeast. I've used this book for years, but am sad to say that the keys presented in this volume are definitively the worst I've ever used for any taxon (mushroom or otherwise, and I have likely used hundreds over the years). Unfortunately this poor key structure seems to be an regrettable trend in all of Bessette's books that I have seen (to be honest, I really don't know why his coauthors ever let him write the keys). The photographs are beautiful, the species descriptions are generally good (though not as good as nor with the attention to look-alike species as Arora's), but the keys take forever and are almost unusable. Instead of presenting a straight-forward dichotomous key, the keys here are polytomous, a feature that already makes them less user-friendly. The first few couplets ('grouplets'?) are useful enough, but he soon degrades into describing every species in a full paragraph in the key. He lists about five or ten of these, followed by a 'none of the above' option, that takes the reader to the subsequent couplet/grouplet of more full-paragraph species descriptions. The result is something that is not a key at all, but a long list of species descriptions that the reader has to plow through, resulting in a keying process that takes twenty times longer than it should. If we wanted to identify a mushroom by using species descriptions, we may as well just read the book cover-to-cover than try to plow through the keys presented here. That said, this is a useful companion book. As I have mentioned, the photographs are beautiful (Bessette's are some of the best I've seen), and this volume works well in combination with Arora's book (which has beautiful keys, descriptions, and better species coverage, but is a bit lacking in color photographs). I don't think this book is worth the list price, but if you can get it on discount it's a useful complement. If you are limited to only one mushroom book (for anywhere in the US) I wholeheartedly recommend Arora's volume, and if you're looking for a well-photographed companion volume for it I would first recommend Roger Phillips' book, followed only then by this volume as a useful third.