Cadence provides a very nice tutorial explaining the NC tools. You'll need to work through it. It takes under an hour. Note: The tutorial references some example files. These are found in /opt/cadence/ldv/doc/ncvlogtut/examples.
Cadence NCLaunch Tutorial - /opt/cadence/ldv/doc/ncvlogtut/
ncvlogtutTOC.html
Using the waveform viewer is also very well described in the same tutorial.
Just a note on some peculiarities. For some reason, the tools work better if you use the bash shell. When using csh, some students found that the nctools would not open correctly, they consistently could not find the necessary object files.