Read reviews on tripadvisor. It is not considered safe to walk around Newark area at night.I suggest you either catch the train into NYC or get a cab to Jersey Gardens Outlet Mall for a bit of retail therapy.
Hi i stayed in the sheraton in December.The rooms are ok very big and you have a indoor swimming pool. if you want breakfast in the morning you have to get up early we had to wait 2 hours for a table. when you arrive at the hotel go to customer service and they will arrange any taxis you want there is a shopping centre (jersey Gardens) near but you will have to get a cab there. but we met afew people in the hotel and we all wanted to go to New York. Taxi was really expensive but someone who worked at the hotel told us a great trick. Outside the hotel is a shuttle bus which takes people to the airport, jump on that and then you arrive at Newark airport again follow signs for the train to New york this train runs from the airport so dont leave the airport, it takes about 30 - 45 mins and spend the night in new york and the best thing is i didnt have to pay a thing. Not sure if you was meant to pay.But Aldrich is right it is not safe to walk around Newark at night.