The [http://network.nhhistory.org/Participating-Organizations.aspx New Hampshire History Network] has an internet site where you can find information about historical societies in many cities and towns of Rockingham County. These historical societies can often be a great source of information for your family history research.
The New Hampshire Society of Genealogists publishes a magazine regularly. They also publish books containing records. You may want to view their [http://nhsog.org/nhsog/
You may also want to go to the internet and type in the name of the town in New Hampshire. Often you will find there is a public library. They can often help you with your family history questions.