This collection was fun to read, although not anything extraordinary and it is all knowledge found on Pottermore. So, other than the covers, it doesn't add anything particularly new to the universe, if you've read all those. If you haven't and don't know where to start, these present themselves as a structured way to find some extra tidbits of the series (some cooler than others).
#1 Heroism, Hardship and Dangerous Hobbies. This is the best structured one. Fun to know more about your favourites from the series.
#2 Power, Politics and Pesky Poltergeists. The structure of this one is a bit more ragged. Fun if you like the politics of the world, the characters hungry for power and status, and/or Peeves
#3 Hogwarts: An Incomplete and Unreliable Guide. The most fun because you're back to witches and wizards and magical beasts, to goblins and ghosts and to magical feasts. Probably the one that delves the most into magic and magical objects of the show.