First things first. You're not going to strap this book under the deck lines of your kayak and start paddling. Aside from it getting wet (and ruining a perfectly good book), it's not that kind of guide book.
What the book does is provide outlines for 44 routes around the Outer Hebrides, from The Butt of Lewis in the north to Mingulay in the south, St Kilda in the west, and crossing from the mainland to the east of the isles. Each route carries information about tide times and directions (except in places like the Sound of Harris where they are rather difficult to predict, as the book makes quite clear), route lengths, variations and escape routes, an outline map of the route, and a description of the route. The descirption includes access and egress information, things to see and places to stop on the way, and lots of well researched background on relevant local wildlife, culture and history. It also provides information about hazards such as tidal rapids and the likely effect the weather will have on each route.
With all this information, and equipped with the relevant OS map (the book tells you which you need for each route) you are now well armed to go and explore the fantastic coastline that the Outer Hebrides has to offer.
However, the guide offers so much more than this. As stated above, there is a wealth of information about local culture, history and wildlife that would be of interest to anyone interested in the Outer Hebrides, and not just sea kayakers. It also contains a collection of fantastic photographs showing you just what you're missing by not being here, and would make a great addition to any coffee table.
For transparency, I know the authors and am a member of Stornoway Canoe Club. However, I paid for my copy of the book and would gladly do so again. It definitely won't get strapped under the deck lines of my kayak though!