Where do you go to look for library job sites? Here are some sites
I've seen. All are free for job seekers to search but some charge
employers for posting ads (which means they may not get the range of
postings that you'd expect.)
Foothills Library Association (http://www.fla.org/jobline.html)
–
by far, my favourite job board. Focused on western Canada, has an RSS
feed, doesn't charge employers to post ads (but encourages them to buy
a $25 annual membership to support the volunteer-run board) so they
have lots of ads from all types of libraries rather than the other ones
I list below which seem to only have listings from big libraries with budgets
for recruiting people. This also forces institutions to choose – one might post to the Partnership while another might post to CLA – but not both which means you're forced to monitor both boards.
The Partnership Job Board (www.libraryjobs.ca)
– Members of provincial and territorial library associations pay $50 for two weeks, non-members $75 to post an ad
CLA Job Board (www.cla.ca – select “Library Careers” from menu)
– pricing ranges from $175 – $300 for 30 days
Most of the library schools in Canada have job boards and allow employers to post for free so they're an underrated resource for job seekers:
SIM (Dalhousie, Halifax – no job board but has career and employment resources)
SIS (McGill, Montreal – no job board)
FIS (University of Toronto, Toronto)
FIMS (University of Western Ontario, London)
SLIS (University of Alberta, Edmonton – no job board)
SLAIS (University of British Columbia, Vancouver – no job board)
Obviously, the jobs section of the web site for any institution you are interested in applying to is a good place to keep an eye on.
There
are probably also job boards for the library tech programs across
Canada, job boards targeted at specific areas of librarianship (the Special Libraries
Association has a job board, there's probably one for health science librarians, etc.). There are also the “big” job sites like monster.ca that post a range of jobs including the occasional one requiring an MLIS or others that might be of interest to MLS grads…but I'm not going to search out all of those! 
Governments of all sizes tends have good job boards. Here's the Government of Canada's job site. Most provinces has similar sites
as do larger municipalities. These types of sites might not have
MLIS-specific jobs but could have others in a related area that
appeals to you.
Finally, a general Google search on some variation of “library jobs Canada” can lead to other aggregators and sources.
Where have I missed?
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