It's a great book. His explorations in Chitral, Hunza and Kashgar really set the blood going. The author of the book retraced a lot of his footsteps, and later went on to write an excellent book about Tibet, so the coverage is really in-depth. The actual Tibetan campaign is pretty shameful for my money, although it did prompt Younghusband's turning to spirituality in later life.
One thing I hadn't realised was that Younghusband also played a role in the fateful Jameson Raid ([wiki]Jameson raid[/wiki] in the Transvall at the end of 1895. Food for thought for all those people inspired by the current Boer War-related thread on this branch.
Enjoy the book!