For anyone who speaks Korean (or wants to learn how the North Koreans write things), then try the defector-run website GoodFriends Korea.
Operated by North Korean defectors in South Korea, the information on the site is used by journalists, intel agencies, aid groups, academics, and others interested in the North. Much of the information is based on defector testimony and reports sent to the organization by North Koreans who have smuggled cell phones back into their country. While little of the info is verifiable by outsiders, GoodFriends provides a quantity and range of info on the North available nowhere else.