The following are the Citizenship and Immigration Canada (CIC) useful links:

Link Description
http://www.cic.gc.ca Main Website. CIC was established in 1994 to link immigration services with citizenship registration, to promote unique ideas all Canadian share and to help build a stronger Canada.
http://www.cic.gc.ca/english/skilled/before-1.html Things to consider before you apply to come to Canada
http://www.cic.gc.ca/english/applications/index.html CIC Applications and Forms
http://www.cic.gc.ca/english/information/applications/index.asp CIC Applications and Forms
http://www.cic.gc.ca/english/contacts/call.asp CIC Call Centre Services
http://www.cic.gc.ca/english/information/offices/missions.asp Visa offices outside Canada
http://www.cic.gc.ca/english/immigrate/provincial/index.asp Provincial Nominee Program