Hi, What time frame are you researching ?
What Provinces are you researching?

Perhaps Posting Surnames, Names of interest could be helpful
There may be persons researching the same families - connections - who may be able to assit.

Census:
Canada Census is available to 1911 Nationwide - 1916 for the 3 Prairie Provinces of Alberta, Manitoba Saskatchewan.
Automated Genealogy Online Census 1901, 1906, 1911

Birth Marriage Death:
There is No National Index for Birth Marriage Death in Canada.
Each Province is responsible for the Vital Events in their area.
Some Provinces have made some indexes available online:
the time line is restrictive.
Alberta: Does not make Index / Records available. All information from the Govt of Alberta Vital Statistics Registry offices -may be restricted - Cost $40 aprox

British Columbia: Marriage 1859-1936 Birth 1872-1903 Death 1872 -1990
Index can be viewed online. Microfilm can be viewed at the Provincial Archive in Victoria - Some Public & University Libraries in the Province. Some Libraries - Genealogical Societies in other Provinces may hold the films.
Latter Day Saints Family History Centres - may hold the films or can be brought in to a local Centre or Public Library.
Information can be viewed at no cost. Transcribed. Photo copies depend on copy machine charges - .50 cents or less in BC.

Manitoba: Index available online -restricted time line
http://vitalstats.gov.mb.ca/Query.php
Birth: 100 years - Marriage 80 years - Death 70 years

Saskatchewan: Index Available Online - restricted time line
http://www.isc.ca/VitalStatistics/Genealogy/vsgs_srch.aspx
Births: over 100 years Deaths over 70 years
Marriages over 75 years [ not indexed -cannot be searched oline ]
Index may not be complete -there are persons I could not find.

Other Provinces may also have index online .

ANCESTRY: Only has access to information that is made available to them. They will not have any Birth, Marriage , Records - that are still considered Private.
only information that is now Public Record.
Information that is submitted re genealogy etc
Ancestry is an Ongoing Project.

Family Search Org : Online - may be helpful -
Also an ongoing project.

Cheers, Stella