Take your time when looking for a pup. If possible, find a local breeder because you want to be able to see what kind of conditions they were raised in. Beware of someone who wants to meet you some place else, as they may have something to hide.
Look for a health guarantee that is comprehensive. If you see one and have questions about it, feel free to post a link to it here and the very knowlegable people will help you decide whether or not it's worth the piece of paper it was printed on. You'll find in your search that the cheaper dogs have "guarantees" that don't really cover anything.
Get familiar with puppy lemon laws that are available in NJ (you are lucky to have them!)
New Jersey Pet Lemon Law
Beware of anyone who advertises "teacup", "minature" or "pocket pups". First of all, there is no such thing, it's a marketing ploy. Second, the smaller the dog, the higher the vet bills tend to be. If someone is breeding females under 5 lbs, stay away! Also, no one can guarantee how big the pup is going to be when it's still 10-12 weeks old.
I am dead set against buying a dog off the internet from ebay, puppyfinders or classifieds. You are rolling the dice on the health of the pup and truthfulness of the person on the other end, IMO. In general, the cheaper the dog, the more shortcuts the breeder took. But that doesn't mean the most expensive is the best either!
Check out the stickies on the main page and in the library about choosing a breeder and a dog.
I second the option of looking in to rescues. I've got 2 rescue babies and they are the loves of my life.
What ever you do, take your time, do your research and avoid pet stores, BYB's and puppy mills. You'll be rewarded for your effort with the best and healthiest dog for you.