The Toronto Star has digitized every daily issue of their paper, from 1892 through 2001, and put them online. It’s all searchable, too. What a monumental task. It isn’t free, but this will make researchers jobs much easier. I hope other newspapers follow suit. For now, you can check out all the 1945 issues gratis. (via mefi)
UPDATE: The Globe and Mail has done the same thing, with every issue from 1844 onward. Not available for individual access, but apparently some public and university libraries have paid the site licence fees.
Paper of Record appears to be a sort of super-database consisting of scanned newspapers from Canada, the US, the UK, and Mexico. This could become a great resource.