Here is a list of free sites some of which we used when compiling this competition.
1940 Census http://1940census.net/
Australian Records http://www.nla.gov.au/
Castle Garden http://www.castlegarden.org/
Cornwall OPC www.cornwall-opc.org
Ellis Island www.ellisisland.org
FamilySearch www.familysearch.org
FreeBMD www.freebmd.org.uk
Freecen http://www.freecen.org.uk/cgi/search.pl
FreeReg http://www.freereg.org.uk/
Google www.google.co.uk
India Family http://indiafamily.bl.uk/UI/Home.aspx
Irish Genealogy http://www.irishgenealogy.ie/en/
Italian Genealogy http://italiangen.org/
Lancs OPC www.lan-opc.org.uk
New Zealand BDM https://bdmhistoricalrecords.dia.govt.nz/home/
NSW BDM https://familyhistory.bdm.nsw.gov.au/lifelink/familyhistory/search;jsessionid=F75C5D1E9CD8DCF26BF0D66571E0858C?0
NSW State Records http://www.records.nsw.gov.au/state-archives/indexes-online/court-records/index-to-criminal-depositions-received-1849-1921
Old Bailey Online http://www.oldbaileyonline.org/forms/formMain.jsp
Papers Past http://paperspast.natlib.govt.nz/cgi-bin/paperspast
Trove http://trove.nla.gov.au/
Probate Search https://probatesearch.service.gov.uk/#wills