Pittsburg, NH is an area popular with those who enjoy riding ATVs, hunting, fishing, and boating and Buck Rub's Hidden Acres Campground is a nice good place to make your base with easy access to trails and lakes. 

I had no problem making reservations online; all sites have water and electric and you can select a wooded or open site. If proximity to the ATV trail is important to you, you may select a site accordingly. Sites were large and most quite level. There are some seasonal campers. The bathroom is rustic, but functional with warm showers. The sites have picnic tables and fire rings.

Check-in was at the main lodging office (they have cabins/lode rooms available as well) across the street. 

If you don't want to cook for yourself, the Buck Rub Pub provides a good menu selection; it's popular and you may need to wait, esp. on a weekend evening. For a quick breakfast or lunch at a fair price, the Happy Corner Cafe will meet your needs. For dessert, check out Moose Alley Cones. And look out for moose and other wildlife, esp. if driving at dusk, dawn, or night!