"Walking on the Orkney and Shetland Isles" by Graham Uney is an outstanding little book that should be regarded as essential reading by anyone considering visiting Scotland's northern isles. Produced in Cicerone's very familiar "small-but-perfectly-formed" format (albeit with one of the highly attractive covers they have introduced in fairly recent times), this is not a book that will weigh you down, but is one you are likely to find indispensable. There are plenty of guides to Orkney and Shetland out there (singly or jointly), but books aimed specifically at walkers seem rather thinner on the ground.
The book includes details of 23 walks in Orkney, and 57 more in Shetland. They vary considerably in length, from many covering just a couple of miles on a smaller island or over a particularly interesting piece of ground, to a few longer ones of up to 16 miles along the Atlantic coast of Orkney's West Mainland. Information about each walk is accompanied by good, full colour mapping and some excellent colour photography. Perhaps the thing to bear in mind above all else is that whatever your reason for being in Orkney or Shetland, you are probably going to be doing part or all of at least some of these walks, making the book of value to you. While some of the walks take in high points and hill tops, others lead you to some of the huge number of archaeological sites that compete for your attention in Orkney, or to points of interest on islands in both archipelagos. You could never describe any collection of walks as "comprehensive", but the index maps show just how impressively intensive this book's coverage is, especially of Shetland.
At the front of the book you find an introductory section providing some background about the northern isles and their wildlife and archaeology. There are also sections about walking in Orkney and Shetland, and on transport and travel arrangements, plus packing, maps and access. These are not the books strongest areas: the John o' Groats Ferry is not listed among the options available to those wishing to reach Orkney, and the book suggests you can get to Shetland by ferry from Stromness in Orkney (it is actually Kirkwall), but these are very minor points that do not detract from this book's "must buy" status.