What's up kids?
I've lived in New Jersey since 1978, when I was but a wee little tyke, and here's what I know:
Places to see metal shows in NJ:
Obsessions, Randolph, NJ (not terribly far from Bedminster, but not too many shows)
Birch Hill Niteclub, Old Bridge, NJ (also not terribly far, but the other direction, almost always all ages shows, no booze)
Club Krome, South Amboy, NJ (never been there, but I think they're all ages as well)
I'm sure there are more as well, but those are the 3 that come to mind.
If you REALLY want to see some good stuff, as in most national tours that come through the USA, you have to go to NYC. Metal shows are regularly booked at:
WWE The World
Irving Plaza
B.B. King's Blues Club
Roseland Ballroom
Good luck, and get your butt to the Metal Meltdown coming up in early March!