These are my favorite sites for doing Quebec, Canada research.
Eastern Townships Archives http://www.rootsweb.ancestry.com/~qceastwn/archives.html
Eastern Townships Research http://www.rootsweb.ancestry.com/~qceastwn/index.html
Library and Archives Canada http://www.collectionscanada.gc.ca/genealogy/index-e.html
Quebec, Canada cemetery records http://www.afhs.ab.ca/registry/regqc_cemetery.html
Quebec, Canada cemetery records: Interment.net Cemetery Records Online http://www.interment.net/can/qc/index.htm
Canada GenWeb Project http://www.rootsweb.ancestry.com/~canwgw/
Missisquoi County (Quebec, Canada) http://www.griffincunningham.net/davis/misscountymain2.htm
Marlene Simmons Research site http://simmons.b2b2c.ca
1851 Missisquoi Co., census (pdf) http://www.daviesgenealogy.com/CENSUS.pdf
Missisquoi Historical Society and Museum