Rather often, I get searches on "NJ night life" or variants of such. Got quite a few recently.
It's a shame because I'm the mother of two school-age kids; I know nothing about NJ night life.
But, luckily, someone else does and decided to write about it. The Star-Ledger has an article this morning titled I Love the Nightlife which should help you find your bars or clubs or whatnot in North and Central NJ. There's also KatManDu in Trenton, somehow open ten years and I still never made it over there (even when I worked a couple miles away.) And don't forget to check out The Crooked Beat, which has calendars, maps and news on brews for bunches of clubs in the NJ and NY area. I also found some news on South Jersey's nightlife- and I admit to having visited several of those places, back before I was a mommy and I had a night life too.
I hope this helps. Now, you go have fun with your nightlife; I'll probably be asleep before you even leave home.