How to make animation in NX?
4 Answers

This video has an explanation! It is very cool!
http://www.youtube.com/watch?v=wlzVc2EbyWQ&feature=related

For assembly animations (not in motion simulation environment): https://www.youtube.com/watch?v=fNZfClY21M8

I have no access to Siemens NX, but on Youtube you find 2 tutorials (without audio), but easy to follow because of the slow speed.
Part 1: http://www.youtube.com/watch?v=SK9z0z_MSJw
Part 2: http://www.youtube.com/watch?v=IPo7797ssuc
Hope that helps.