The Drouin Collection (also called Quebec Catholic Parish Registers, 1621-1900) contains a huge amount of church records (mostly baptisms, marriages and deaths) filmed by the Institut Généalogique Drouin sometime in the 1940s.
There are some records after 1900, but most are before.
The records appear in their original format (although some were clearly re-written before filming) mostly in French, with some of the older ones in Latin.
You can pay money and find them on ancestry.com.
If you know what person/date/place you are looking for, you can find them for free at familysearch.org listed under Canada/Quebec Catholic Parish Registers, 1621-1900.
Go there, choose the City/Town/Parish that your person is from and then the date. Browse through the pages of the images until you find what you are looking for. It's a bit tedious, but very rewarding once you find the record you are seeking.