The living situation at UMDNJ/Kessler is pretty nice. You spend more of your time in West Orange (where Kessler is located- a very nice suburb) than you do in Newark. Newark has some nice areas, actually, but overall only a few residents live there. If you check out the UMDNJ website, they have some suggestions of where to live.
When I was a resident there, I lived in Montclair for 2 years, and Berkeley Heights for another year. Montclair is a fun city in its own right- it's a college town with a fun little downtown area, great affordable resteraunts, cute little shops, very safe. It's where Yogi Berra, many of the NY Giants, SI columnist Peter King, and many NY city business people live. Very nice area.
Berkeley Heights was a nice, quiet suburb, most notable as the home of Bell Labs.
There are plenty of nice neighborhoods in close proximity to UMDNJ- Summit, West Orange, Springfield are all nice neighborhoods popular with the residents.