Important Note: Even though this manga has the same as the anime it's "adapting", it is actually a requirement to have watched the first and second season of the Magical Girl Lyrical Nanoha anime series first. The reasons for this are that not only is this series more of a complement to the anime, none of the anime scenes are actually adapted into the series, and there are spoilers from the anime in this.
As I just said, this manga is a complement to the Magical Girl Lyrical Nanoha A's anime. All the different chapters show events that actually happen before, after, and even in-between the
Nanoha A's manga.
To be precise Chapters 0-3 take place before the Nanoha A's anime, Chapters 4-5 are events that happen during Nanoha A's, and 6-7 are events that happen directly after the anime ends.
All the chapters go through the viewpoint of Nanoha, Fate, Hayate and all of their comrades and friends and how they interact with each other. In fact, if you're hoping for more action in this manga series, you may be disappointed as the majority of this series are just the main characters interacting with each other.
Nevertheless, I really enjoyed reading these chapters. While I did like the action of the Nanoha A's manga, I wish it had more character interaction and this manga definitely didn't disappoint in that regard. If you didn't get enough of Nanoha/Fate's school life or if you wanted the conclusion of A's anime to be longer then you'll at least like this series.
The Art of this series is good, it has all the great character designs from the anime.
Overall, I thought this was a very enjoyable short series, and think that anyone who enjoyed the Nanoha A's anime should at least give this manga series a try.