I've only ever worked with camera's and always had someone else doing the sound when I've worked on short films, but now I'm working on my own trying to get experience filming Live Music. I just did my first gig using only the mic on the camera (I know, I know...ssshhhh!), which was surprisingly good but, obviously, not quite good enough.
Currently, I'm thinking about taking a feed strigty off of the P.A. into the camera but I really wouldn't have a clue what to use or where to find it....or even if that's even remotely a good idea!