New england camping in april

Where are you trying to go? New England is a big place. If you are looking for Eastern MA, I would second the recommendation of Normandy Farms. We used to live out there and did many spring weekends at NF. Indoor pools, nice facilities, and relatively quiet at that time of year. It's great for day trips to Boston/Providence/Plymouth, etc...

I'm not sure I'd be apt to go much further north until late April or May.