When hiking from sea level up to ~500m it will be all fine and dandy. Above
500m things start to get tricky, after you pass ~700m be ready for very steep
slopes.
ut.no - Hiking/biking trails aggregator (in Norwegian)
If you're traveling by car, here's a list of scenic
routes worth driving through
Czech application Mapy.cz has proved very useful around
both Bergen and Hardangerfjord, it contains high quality hiking maps
Weather website served by the Norwegian
Meteorological Institute