The first place to start is FamilySearch and Ancestry records but not family trees.
Then I'd look at the Buxton-Hollis Historical Society website, www.boxtonhollishistorical.org/researchlibrary.html
Almost every Town Clerk has vital records prior to 1892. You can contact them and ask when their records start.
That should get you started. Then when you can't find a record, post a request on the Message Board where you think the answer will be found. Each county has their own resources. Successful Searching!