Although out of print, you can still find it used as well as new in some book shops in India. In addition to treks, Trekking and Climbing in the Indian Himalaya, covers many trekking peaks as well as a couple more technical ones.  I used this book as an outline when I climbed Chamser Kangri in Ladakh.  The practical information is pretty brief on the treks and climbs themselves and there is a lot of extra nonessential information and pictures that makes it pretty heavy to trek with, but the book covers some interesting routes and peak not covered elsewhere.

The Cicerone Trekking in Ladakh guidebook is the most up to date guidebook for trekking in Ladakh. It covers most of the information needed for trekking on your own including water sources, trekking times, and accommodation. Treks covered: Across Zanskar, Round Sultanlango (Zanskar Region), an alternate route from Padum to Lamayuru via the Kanji la, "Hidden Valley" area to Alchi, and the Markha Valley.