Wonderful website by a group of French climbers and enthousiasts featuring different ranges of northern Pakistan. Nice maps, and some descriptions and reports too. Just take a look and enjoy.
John Mock and Kimberley O'Neil on trekking in the Pakistan Karakoram and Hindu Kush. You may find some useful information here.
Website by two Japanese researchers (anthropologists?): Jun Maruyama and Reiko Kojima, giving some interesting info on Chitral, and the Kalash area in particular. Alas, partly in Japanese, and last updated in 2003.
Tour operator based in Chitral, specializing in treks in Chitral, but also in other parts of northern Pakistan. Nice website giving some interesting background info too.