The introduction to this work explains not just the pivotal role of dragons in fantasy role-playing, but that with systematic advances that allow for varying ages and sizes, dragons can now be presented at a range of challenge levels appropriate to any group of characters! Much of the ground-breaking work and number-crunching has been done by the people maintaining the D20PFSRD website, and they have been kind enough to allow their work to be used here. Excellent cooperation in the true spirit of the game! The good news is that this is just the first dragon book planned...
So, this product is all about black dragons. They live predominantly in swamps and marshes whatever size or age they happen to be. They are solitary in nature, liking caves beside (or even under) fetid pools in which they wallow in mud and dirty water... but can have some interesting items in their hoards, should you find a way to get at them. Their preferences for treasure tend towards that which does not rot (so coins, gems, and metal artefacts predominate) while they do like their food, shall we say, well-aged... rotten, if you prefer.
The bulk of the book is taken up with stat blocks for black dragons of all sizes and ages from mere wyrmlings little larger than a cat (and presenting a CR of just 3) up to a great wyrm with a challenging CR of 19. Each one comes with plenty of detail including a run-down of likely items to be found in its hoard, as well as combat tactics and variations galore. The hoard data comes with gp values, making it simple to swap things around without destroying balance, and there are also suggestions as to how the dragon may actually use some of the things he's got, rather than merely sit around admiring them. A section called 'Upping the Ante' gives ideas of how to make each dragon a formidable, thinking, opponent; while there are suggestions for variants on the basic build as well.
All in all, this is a tremendous resource if you want to challenge your characters at any level with a black dragon specifically... or if you are building an ecology in which black dragons feature, or intend one to be a recurring enemy - or even acquaintance - growing in capability as the party progresses and becomes more powerful.
[4 of 5 Stars!]