Well readable but suffering from a bit from chaotic construction.
First things first, this story reads well, with memorable characters and interesting ideas. If you are looking for something to take your minds off things, stop reading this and start reading the preview, I guarantee that you'll like it!
That said, the book could use a bit more polishing. Starting with the big picture, it would profit greatly from getting split into two, uneven parts, at about 60% point. The first part is very good, with good pacing, interesting situations and dialog that will evoke a grin. It has, however several drawbacks that I will discuss later.
The second part is obviously weaker -- but that does not mean it's weak! Despite the fact that story gains a real -- and really fearsome -- antagonist and a very powerful motive, the narration, along the flow, become bit rocky and uneven. Some scenes are very well fleshed out, with little details showing through, suggesting the breadth of author's imagination, while others seem to be barely sketched.
The biggest problem with the whole book - and the first part especially - is the lack of good character descriptions. Wherever we get them, they often are reduced to brief passages, two, three word long. This is compounded even further by the fact that there are not just humans and dragons in the story; there are twenty one species, of which only two get a strong, recognizable and memorable descriptions!