Essential. There are some other Tajikistan travel guides in progress, but at the time of writing the 3rd edition Lonely Planet is the only practical option. Make sure you have the 3rd edition of the guide (published in 2004), as previous editions had very poor coverage of Tajikistan.
This book includes several itineraries in Tajikistan, including the Fann Mountains to the
west of the country and routes in the Pamirs taking in the Wakhan Corridor and lakes Sarez and
Yashikkul.