Of course there is required reading for the courses, but you may want to pick up an inexpensive paperback for recreational reading along the way. There are several good bookstores in Kathmandu. Camera and Film A good automatic camera with zoom and panoramic features will work great. Bring lots of film. The scenery is spectacular and the culture fascinating.
Film is expensive in Nepal, more so in Tibet.
If your camera has a battery operated shutter, bring spare batteries. Binoculars Optional, but handy. Money Belt Useful for keeping passport and money safe. This list is intended as a guideline. Also, you may have individual items that you enjoy or that make your trekking experience more comfortable.