Nagarkot is a hill statill just less than 2 hours drive from Kathmandu and is very famous for sunrise and sunset sightseeing purpose. Also, if you are lucky with the weather, you might get a good view of the himalayan range from Nagarkot.

While in Kathmandu, you shouldnt also miss bar hopping in Durbarmarg and Thamel.

Check this webpage for more practical info: http://wikitravel.org/en/Kathmandu

Bear in mind that its cold in Kathmandu now, so have some warm clothes with you!

Enjoy your trip!