Check out the following website
www.drive.drive-alive.co.uk/drivinginnorway for legal requirements, also the NAF (Norsk Automobile Forbund) which google can translate for you. The Norwegien police are very strict, with hefty on the spot fines for speeding, and you won't be allowed out of the country until you've paid! Also be aware that they have disguised speed traps, so you won't know until you've been pulled!
What front brake are you using, I would reccomend upgrading from the single leading shoe drum, as Norway is very steep! (Actually there is a lot of flat land in Norway, problem is it's all vertical!)
Another thing to watch out for is that traffic entering onto the road has right of way, except those roads marked with a yellow diamond.
A few useful translations:
bensin; petrol, gas,
bleifri; unleaded,
to takt ol; 2 stroke oil,
dekk; tyre
forgasser; carburettor,
cart, map
unshyld jeg er utlander, sprekke du engalsk?: Sorry I'm a tourist, do you speak english?
All the above aside do enjoy your trip