With regards to siblings, census records help a lot, but not just census records, but wills and obituaries, etc. Solved a huge family mystery by getting the will/letters adminstration of one brother which included letters from another brother. The obituary of yet another brother included details of the family migration from the Niagara region of Ontario to Trafalgar Township to Essex County - again helping piece together another mystery. Church archives can be very helpful as well. The United Church of Canada archives in Toronto include records from many of the churches that amalgamated to become the United Church, such as the Weslyan Methodists. There are journals written by some of the old circuit preachers which include details of what life was like in some of the earliest communities. There are old tithe records, church meeting minutes, as well as a few birth/baptism records.