Dude, you're going to have a great time. The northeast US has some great craft brewers. These other guys have covered some Boston area stuff, although there are more.
http://beeradvocate.com/beerfly/city/3 that's a good source of info for you, with reviews and the like.
For NJ, there is Flying Fish in Cherry Hill, and if you're in Cherry Hill you're just a stone's throw from Philadelphia, where there are a boatload of excellent breweries/brewpubs/beer bars in the city proper and surrounding areas. Here is the listings for Philadelphia.
http://beeradvocate.com/beerfly/city/13 Some of my favorites: Zot (good prices, Belgian cuisine and beers, really knowledgeable staff), Monk's Cafe (lots of Belgian stuff here as well but they feature a lot of other craft beers), Nodding Head and Dock Street (both brewpub/restaurants). Eulogy, Triumph, Standard Tap, National Mechanics (don't go during 'clubbing' hours - too loud, no table space) ...I could go on. You can basically just wander around and stop wherever looks intriguing.
And once you're in Philadelphia you might as well drive down into Delaware to check out Dogfish Head. If you're into strong ales it'd be worth the trip.
However, if you're in the northern part of the NJ or are driving from NJ to Boston or vice versa, you can always go into New York and check things out there: Brooklyn Brewery, Ommegang etc. BeerAdvocate has a page for NYC as well.
Have fun.