I've lived in Arkansas for all of my 24 years of existence and some might say that is 23 1/2 years too long. All kidding aside its not too bad here. I don't live near Pine Bluff but I know enough about to give you some pointers.
What has been said about the racial make up of the city is true. It is split 50/50 and it has its good parts and bad parts, but I don't know exactly where those are. I know if you need a place to live, White Hall which is about five minutes up the road from Pine Bluff is a good option. My former boss grew up in that area and always speaks highly of it. At last check, his mother still lived in White Hall.
The Razorbacks drive the sporting pulse of the state. Being so close to little rock I would say 95 percent of the people will be Razorback fans in your area. I'm sure they will also pull for UAPB, but the Razorbacks come first. Even in the northeast part of the state where Arkansas State is located, which is a D-1 school, the Razorbacks rule.
High School sporting wise, Pine Bluff high school played in the 7A state football championship a few years back. Dollarway, which is also in Pine Bluff, is an athlete factory as well. Watsons Chapel also tends to be very competitive. Plenty of good sporting events to cover. Little Rock is about an hour away from Pine Bluff and provides some nightlife if you are willing to drive. I can't speak to what Pine Bluff has in night life but I imagine it isn't much.
The crime rate in Pine Bluff tends to be high, but I'm sure its like most places. If you are smart and keep your wits you can stay safe. Pine Bluff also has a paper mill and yes it smells......badly. You do get used to it, but your first few weeks could be tough. There is also a weapons arsenal for the U.S. Military in Pine Bluff. I've driven by it and it has always looked kind of cool but I've never stopped to see how close you can get to it.
As far as Arkansasans go we are generally a friendly bunch. If you are from the north we do have accents, but so do you so live with it. We say things like yall and enjoy Sweet Iced Tea. We will fry anything (I've had fried Racoon and Snake prepared by my grandmother). The weather sucks. Temperatures can reach in the 100s in the summer time and below freezing in the winter. It generally snows a few times a year, although you might be far enough south to miss all of that. We also live in tornado alley. January-May tends to be the most active. Just be aware that storms will happen and tornados can occur. August is usually the hottest month. The humidity sky rockets sometimes to 70-80 percent with temps in the 90s. It isn't fun. Mosquitos can be a problem in places, not sure about Pine Bluff though.
All in all enjoy your time. If you'd like to know anything specific feel free to ask or pm me and I'll do my best to answer it.