Some useful links

Ancestors from Norway
Johan Ingvald Borgos' web-site
DIS Norge - A Norwegian Genealogy Association
DIS Norge - A Database of Genealogy Researchers
The Norwegian Genealogical Society (Norwegian)

The National Archives of Norway
The Digital Archive of Norway
Avfotograferte slektshistoriske kilder (Norwegian)
The Norwegian Historical Data Centre, University of Tromsø
Diplomatarium Norvegicum
Oluf Rygh: Norwegian Farm Names

Norwegian Libraries (Norwegian)

Nils Johan Fosli: Genealogy in Mid-Troms, Norway
Arne Lundenes: Finnish Emmigrants to Northern Norway

Specific topics
Norwegian naming practices (Johan Ingvald Borgos)
Norway map and the counties of Norway (Johan Ingvald Borgos)
The counties and communities of Norway (German)
The nordic characters (Johan Ingvald Borgos)
Slekts- og lokalhistorisk forening i Tromsø (Norwegian)

The Danish State Archives
Parish registers and Population censuses - Digitised (Danish)
Dansk Demografisk Database - Search in databases with historical sources