Major tourist attractions of Nepal

Trekking: Trekking is one of the best way to explore and experience Nepal's unbeatable combination of natural beauty and cultural riches. If you are reasonably fit, have a spirit of adventure and are not afraid of walking in the mountains, you qualify for it. The entire length and breadth of the kingdom is a paradise for trekkers. There are easy and strenuous treks lasting from a few days to several weeks. All of them have great scenery. Some of the best know trekking regions are:
1) Everest Region (fe Everest Base Camp or Gokyo trek) 2) Annapurna Region (fe Annapurna Circuit, Annapurna Base Camp or Jomsom trekking) 3) Langtang and Helambu Region (fe Helambu circuit trekking)
Mountaineering: It is another prime attraction of Nepal. Mountaineering can range from climbing the highest peak of the world to climbing lower peaks.
Mountain flight: For those who can not withstand the rigorousness of mountain climbing there are mountain flights which fly around Mt. Everest. Mountain flight offer passengers a spectacular view of the Himalayan peaks. The one hour mountain flight takes with in camera range of some of the highest peaks in the world.
Booking a trekking in advanceIt should not be a problem to book your trekking directly through a Nepali travel agency while still being in your homeland. There are plenty of reliable agencies and the good ones at least need to be registrered with the TAAN (Trekking Agents Association of Nepal) organization and deposit a significant amount of money into a government warranty fund. If you are hesitant just ask for copies of these documents, check this link for some examples.