The Concord Monitor, the local newspaper, can be a useful resource to locate housing. Many landlords with property to rent in Concord will place advertisements in the Monitor on a regular basis. Their website is www.concordmonitor.com.
The Union Leader & New Hampshire Sunday News is another newspaper that may be useful in locating housing. Because of its wide circulation base throughout the state, landlords in Concord may list rentals here as well. Their website is www.unionleader.com.
Craigslist is a centralized network of online communities, featuring free classified advertisements (with jobs, internships, housing, personals, for sale/barter/wanted, services, community, gigs, resume, and pets categories) and forums on various topics.