If you ever travel Nepal, you MUST do some sort of trek. This was on the way up to Annapurna Base Camp. The best part of this 9 day hike was the day we hiked up to the base camp. All you could hear, whilst the mountains created massive walls around you, were the crunching of the snow under your boots.
We did this hike during the first week of January (off-peak season), which meant less people and far more snow along the way, amounting to beautiful views and a few slips here and there on icy rocks.
For the rest of the trip through Nepal, we travelled through Kathmandu, Pokhara (for the hike) and a safari in Chitwan.
Buy a good set of boots and wear them in weeks before the hike (to prevent blisters). Any other equipment or clothing can be easily rented or bought in Nepal.