Probably the most important source of online news are the sites of the Canadian Broadcasting Corporation (CBC), the Canadian public radio and television network, with its French-Canadian sister organisation, the Société Radio-Canada (SRC), and its international branch, Radio Canada International (RCI). You get live radio and selected video material plus local sites from all over the country. Their online archives provide selected material from the past 70 years, news are searchable from 1998 onward for free. Additionally, there is an institutional site with corporate and historical information.
The most important private news enterprise in Canada would probably have to be CanWest Global Communications (Asper family), which acquired most of the Canadian media interests of Conrad Black's Hollinger group in 2000. Their web portal gives you access to newspapers from across the country (e.g. Montréal Gazette, Ottawa Citizen, Vancouver Sun) and to Global TV. The National Post with its business supplement, the Financial Post, is the only paper left with an "independent" internet presence.
Next in line for us is Bell Canada Enterprises with its interests in Bell Globemedia. Their main portal (as well as their local portals) will probably not prove excessively useful, but they also own the most important national newspaper, The Globe and Mail, with its business supplement, the Report on Business, as well as the national television channel CTV.
The Power Corporation of Canada also has a publishing subsidiary, Gesca, with seven daily francophone newspapers in Québec and Ontario (e.g. La Presse, Le Soleil) which you can access through a common portal.
Of lesser importance among the large private media conglomerates are Rogers Communications and Quebecor. The former now owns the Canadian weekly Maclean's and a business magazine, Canadian Business, the latter a portal and a chain of "yellow press" papers in English Canada (with a common news portal). Additionally, they own Le Journal de Montréal and Le Journal de Québec (submerged in their french portal) in Québec.
Two specialty broadcasters are of particular relevance to us, namely History Television, which features some online information and video clips, and the Canadian Public Affairs Channel (CPAC), which you can watch online.
The Canadian news agency and distributor of The Associated Press (AP) is The Canadian Press (CP). The government institution responsible for overseeing the media and telecommunications industries is the Canadian Radio-television and Telecommunications Commission (CRTC).