A First Look at the 1921 Census of Canada

Have you been burning up the internet lines to ancestry.ca/census which is your link to the 1921 census images. It took me about 30 minutes to find my only known relatives in that census, in Saskatchewan. I had the township, range, etc for the property, but not the district so a bit of trial and error was involved in finding that. There were only 21 images to browse through. Kudos to Ancestry, the images downloaded quickly.
To use these browse files you need a good knowledge of the local administrative geography. There are drop-down menus for province and district within the province. A map of the districts would be helpful, but alas!
The Electoral Atlas for 1895 at http://www.collectionscanada.gc.ca/electoral-atlas/index-e.html may help a bit, although not for the Prairies which hadn't joined confederation at that time.
For cities directories are a boon. There's a 1923 city directory for Ottawa at http://archive.org/details/ottawadirec192300midiuoft which helpfully gives the ward for each street. For Toronto a 1921 directory is online at http://archive.org/details/torontodirec192100midiuoft
Once you find the image you'll realise it's a good idea to have a printout of the headings for reference to save having to scroll to the top of the page all the time. The columns are:

• number of dwelling in order of visitation
• number of family, household, or institution in order of visitation
• name of each person whose place of abode was in the household
• place of habitation
• tenure and class of home (owned or rented, rent paid, class of house, house occupied by family)
• sex
• relationship of person enumerated to the head of household
• marital status (single, married, widowed, divorced, or legally separated)
• age at last birthday
• country or place of birth (if Canada, specify province or territory)
• country or place of birth for person’s father and mother
• year of immigration to Canada, if an immigrant
• year of naturalization, if formerly an alien
• racial or tribal origin
• nationality (country to which person owes allegiance)
• can speak English
• can speak French
• religion
• can read and write
• months at school since September 1, 1920
• chief occupation or trade
• employment other than chief occupation or trade, if any
• employer, employee, worker, or working on own account
• principal product, where employed (e.g., ‘in drug store’, ‘on farm’, etc.), or nature of work
• total earnings in past 12 months
• currently out of work
• number of weeks unemployed in past 12 months
• number of weeks unemployed in past 12 months because of illness

While the images I encountered were reasonably good there were several marks added when compiling statistics which make some data illegible.
Some images are missing. Please post a comment to let others know.