These are a few links to FREE sites that I have found particularly helpful in my ancestry quest:
Halton County Historical News and Information – search the Halinet database for historical newspaper records, images and maps.
Ontario Cemetary Finding Aid – search the database for burials in a large number of Ontario cemetaries. Please note that not all cemetaries are included.
Church of Latter Day Saints Records – Family Search – the database has the largest collection of genealogical information and sources.
Olive Tree Genealogy – Lorine McGinnis Schulze has created an amazing website with tips about starting your own genealogy as well as links to tons of information about Canadian and American ancestry.
Archives of Ontario – Houses archives from across Ontario – some can be found online. Also gives information on how to find the information you are looking for within the Archives.
Library and Archives Canada – great information for anyone looking for their ancestors in Canada. The collection on the military is currently being digitized.