Norway has less than 5 million inhabitants, but it is a large country and sparsly populated. Foreign visitors typically underestimate distances and traveling time. Norway's mainland spans about 15 degrees north-south, same as the distance NY City to Miami. From the southernmost point to the border with Russia there is about 3000 kilometers. Norway is larger than Germany and mainland about 3 times longer, Norway is slightly smaller than California but 3 times longer. Norway's gross coastline is an incredible 25,000 kilometers when fjords are included (longer than the continental US coastline and thus one of the longest in the world), and around 100,000 kilometers when islands are included. Norway is both an eastern and a western country, as the eastern most town on the mainland is further east than for instance St.Petersburg, Kiev and Istanbul. Whereas the city of Bergen is further west than Cologne, Geneva and Milano.
Finnmark, the largest and most northerly county, is larger than countries like Denmark, the Netherlands or Switzerland but there is only 70,000 inhabitants. Kautokeino, the largest administrative district in Finnmark, is about the size of Lebanon or Jamaica.
Topography along the coast, fjords and mountains is complex, and public transport is often limited to one bus a day. It is not possible to "see" Norway in a few days. Visitors coming for a few days need to focus on one or two cities or one region. For instance, driving north-south may take several days (not including sightseeing and detours).Many first time visitors make too tight and detailed schedules months ahead, and do not allow time for the unexpected (in terms of attractions, transport difficulties etc).
Because the country stretches far North, a crucial question is how much to the North? This depends on days, wishes, itinerary. Norway is full of great places to visit, while proceeding to the North you can go to Ålesund, Trondheim, Lofoten Islands, even North Cape at the Northernmost tip. One can even visit Svalbard near North Pole which is a guite demanding trip though.
While Norway is a very modern country with plenty of well-organized tours and transport services, abundance of space and long distances makes it ideal for the self-reliant traveller. Travellers willing to invest the extra effort and venture into the unknown will be rewarded.
Advice: Plan trip according to type of transport available and travel times. Do not make too detailed and tight schedules (particularly in winter). Get a good map to start and sketch some rough initial itineraries.