I found this to be very informative in regards to the origins of Gnolls. It was very clear in writing style and I found myself able to dip in and out very easily (since I was following the better half around on a shopping spree and was reading it on my phone). Points and facts were clearly backed up with direct references to where the author had obtained the information, and the quoted parts were clearly labelled.
The only bad parts I could really poke about was that it seemed to be over a tad too quickly. The pacing of the overall document seemed to get into the real essence of what Gnolls were all about, and then suddenly it was over. Not being an author myself however I cannot really offer advice on how this could have been avoided.
Overall a thoroughly enjoyable read.
[4 of 5 Stars!]