Nice initiative Matthew!
Generally, I have found most Canadian provinces have a searchable database: Nova Scotia, PEI, NFLD, MB, SK and BC (though I agree with you about the extent of NB's information). I use FamilySearch for Ontario and Quebec, though our experts may have better suggestions, and the Library and Archives Canada site has wonderful resources online as well, such as the Book of Negros, ship information, and my grandfather's WWI army record, along with the War Diaries for his unit.
The challenge for me is to go back before Canada was founded in 1867, as much of this information isn't available in the free searchable indexes on government sites. I tend to say away from published genealogy databases, particularly those that are not sourced, though it is tempting sometimes.
FamilySearch has some rich resources in their catalogue, for instance, they have a digitized version of the Thomas Brenton Smith collection in Queens County, Nova Scotia, and the Brownson mansuscripts are super-helpful for identifying what may be behind a paywall for early Barnstable County, Massachusetts families. Other colonial Massachusetts records are found here: https://ma-vitalrecords.org/.
I often use local history books and family genealogies to inspire my research - those that are out of copyright may be available on archive.org, hathitrust or google books. But I would check out the information that's already recorded in WT space pages: https://www.wikitree.com/wiki/Category:Source_Directories, and any project resources published for the location you are searching. For example the Atlantic Canada resources are here: https://www.wikitree.com/wiki/Space:Atlantic_Canada_Resources and the Canada Project are found here: https://www.wikitree.com/wiki/Space:Sources-Canada
Perhaps your research will identify links that you can add to these lists?