Norway is an absolutely beautiful country, particularly along the coast. In the south, it's a bit more flat, but in general the entire country is very mountainous. Thousands of tiny islands dot the Norwegian coastline, making it an ideal spot for a sailing vacation. It's also very popular amongst fishermen and, in the winter, skiers.
Norway is not known for its monuments. The thing to see here is the scenery, though if you really want to, you can go and see a variety of different Viking museums and the like. The most famous thing I know of in Norway is a giant glacier, somewhere around the middle of the country.
Not only is Norway very mountainous, but it's also very far north. The combination of the two make it bitterly cold in the winter, and somewhat unpredictable in summer. Norway gets quite a bit of rain in summer and snow in winter, though you can also experience temperatures as high as 24°C.
Norway is expensive. Really expensive. A 1.5L bottle of Coke here costs about $3. A hamburger and fries is almost $10. Most youth hostels cost about $20/night for a bed. Campgrounds cost as much as $15 for one person and a tent. There is no such thing as cheap food in Norway, even at the cheapest supermarkets. If you're going to Norway, bring more money than you think you'll need, and then some.
The financial saving grace of travelling in Norway (for me, anyway) was what they call "every man's right," which says, basically, that you can camp virtually ANYWHERE, for one night. Even on private property, as long as you are more than 150m from a person's house and don't disturb anything (so don't squash somebody's crops), you can camp anywhere you want. I have taken advantage of this quite a bit, and it has saved me a tremendous amount of money in accommodation.
Food was so expensive in Norway that I hardly ate anything, literally. I just about choked on my tongue every time I went to buy groceries. Supposedly there are some great places to get fish in Norway, and they're supposed to be "cheap," but cheap by Norwegian standards probably means about $20/person, so I didn't spend too much time looking. I did, however, have some absolutely fabulous salmon (albeit a very small portion) at the youth hostel in Trondheim, so I believe that it exists.
I've generally found people in Norway to be friendly and helpful, but it is certainly not true that everybody here speaks English. Most younger people have studied it in school and will understand you if you speak slowly, but many older people do not speak a single word of English. Many others, of course, are quite fluent.
Norway is an incredibly clean place. Even in the cities, I have seen very little trash in the streets. Along the highways there are discards here and there, but it's minimal in comparison to many countries. I camped most of the time, so I can't say a lot about accommodation.
Norway is very mountainous. It's beautiful no matter how you travel, but if you travel by bike, prepare to gear down and push hard up some long, steep hills.
Norwegian roads are well maintained, but the cycle paths can be confusing. They tend to stray from the road just far enough that you can't get back onto the road, and then they go off in some completely different direction, getting you completely lost and forcing you to get back on track by some really obscure route.
I had a funny experience while travelling in Norway: the road I was cycling on suddenly said no bikes allowed, and provided no alternative route. There was, however, a road into a small village, so I took it and figured I'd ask directions. The first woman I talked to spoke no English, and directed me around the corner to a man who I believe may have been her husband. When I asked him if he spoke English, he gave a huge grin and proudly said "Yes, a little!" When I explained my plight, he told me "Norway does not have so much traffic. You can cycle on that road with no problem, especially at this time of night." I asked if the police would give me any trouble. "You can cycle on that road without any problems, I guarantee it," he assured me. With that, I went ahead and cycled on the motorway, and as he assured me, I had no problems (except that the road was incredibly steep and long).