I was first introduced to cscope through my job at Cisco. At that time, I never cared much about it. But now I realize it's one of the major productivity enhancement tools where source navigation through a pile of code written by many other people is concerned.
This document provides a tutorial on how to set up cscope for large projects, using the example of the linux kernel.
And this document teaches how to use cscope very efficiently from within vim.
Also, there are many other frontends to csope besides the simple ncurses based one. Try kscope.