The town of Chatham has been separated from the parish since it was incorporated in 1896.
The area of the parish is 22.26 km2 (8.59 sq mi) and the population in 2011 was 522, an increase of 4.0% from 2006. There were 265 dwellings counted. The population density was calculated at 23.5/km2 (61/sq mi). The population was 2% French-speaking and 98% English-speaking.
'Wikipedia lists the following settlements now in Chatham parish. None of them are incorporated municipalities. Those in italics are small and redirected here. The Napan hamlets have been transferred to their central community in Glenelg Parish. Taintville has its own page in WeRelate. Each settlement has a page in Place Names of New Brunswick.
The FamilySearch wiki. This lists the availability of vital statistics indexes for New Brunswick.
New Brunswick GenWeb. A round-up of a lot of genealogical information at the province, county and parish level. Lists of cemeteries and monumental inscriptions can be found here.
The Provincial Archives website titled The Placenames of New Brunswick has maps of all of its parishes and descriptions of some communities within them. This site contains "cadastral" maps for each parish illustrating the grantee’s name for land granted by the province. These maps are cumulative, showing all grants regardless of date.
Microfilm images of all Canadian censuses 1851-1911 are online at Library and Archives Canada, as well as at FamilySearch and Ancestry. The 1921 census appears to be available only at Ancestry.