The Norwegian Mapping and Cadastre Authority (Kartverket) is the national mapping agency of Norway. It operates Norgeskart, an open and free geo portal for the Norwegian mainland. The application here displays a variety of maps from Norgeskart in Google Earth. Requests are limited to 10,000 tiles per user and day.
To get started, have a look at the main page and the FAQ to see how it works. Then either
Currently (version 10), there are 4 overlays related to Norgeskart Maps (Norway):
Do you have comments, bug reports, or suggestions for other map sources? Please leave them below.