I try very hard not to cuss in front of my son, but fail many, many times. My wife is a lot better at it than me, but it does slip out at times. She nor I have once heard a cuss word come out of our sons mouth.
We do not restrict what music he listens to. We are a little more careful about what he sees, but I crank The Who when we are in the car and a lot of times he doesn't even pay attention.
I have noticed that parents who make a huge deal of "bad" words end up accidentally giving them more importance than needed, which in turn shows the child that they can be naughty or get attention by using them.