Budget holiday and Norway don't really belong in the same sentence together. When I first moved to Norway, I camped around Bergen for a few weeks until I found a flat. Since I didn't really know the area beforehand, I ended up having to stay in hostels for a few nights, which are much more expensive here than in most other countries. Transportation and food are also surprisingly expensive.
The right to access is great, but it can be really difficult to find a viable spot within a city. Also, some areas (like the mountains around Bergen, which are the most obvious places to find a spot) don't allow camping at all, or only in designated pay spots. Not to mention the weather is sort of miserable right now, with high winds and heavy rains, a regular event this time of year around the fjords. Hopefully it will be better for your trip:
http://yr.no
Much of the undeveloped land that's easy to reach without a car or good knowledge of the area is too vertical to pitch a tent anyway. It's important to do your research now to find camping spots, so you don't spend hours wandering around aimlessly. It's definitely possible to camp, but you need to know where you're going before you get here. I recommend Wikitravel for travel information in and around cities, and contacting the local tourist bureaus for camping possibilities (preferably before you leave):
http://wikitravel.org/en/Main_Page
http://www.visitnorway.com/en/Articles/Norway/Fjord-Norway/Region-Stavanger/Tourist-information-in-Stavanger-and-Sandnes/
http://www.visitnorway.com/en/Articles/Norway/Fjord-Norway/Bergen/Tourist-information-for-Bergen/
You should also be aware that bus and boat are the only options for travel if you don't have a car. Trains don't run between these cities without going most of the way to Oslo and back. I recommend using the Fjord Tours site to plan your itinerary for trips around the various fjords. The prices they quote for the trip are just the actual travel costs using the recommended transportation, and timetables are accurate and helpful. Buses are regular in Norway and go to major tourist sites, but not very explanatory. Again, you will do much better to plan your routes ahead of time.
http://www.fjord-tours.com/default.asp
http://www.visitnorway.com/en/Stories/Getting-here-and-around/
http://www.nsb.no/?lang=en_US
http://www.rutebok.no/nriiis/Default.aspx
http://www.fjord1.no/en/
The right to access is great, but it can be really difficult to find a viable spot within a city. Also, some areas (like the mountains around Bergen, which are the most obvious places to find a spot) don't allow camping at all, or only in designated pay spots. Not to mention the weather is sort of miserable right now, with high winds and heavy rains, a regular event this time of year around the fjords. Hopefully it will be better for your trip:
http://yr.no
Much of the undeveloped land that's easy to reach without a car or good knowledge of the area is too vertical to pitch a tent anyway. It's important to do your research now to find camping spots, so you don't spend hours wandering around aimlessly. It's definitely possible to camp, but you need to know where you're going before you get here. I recommend Wikitravel for travel information in and around cities, and contacting the local tourist bureaus for camping possibilities (preferably before you leave):
http://wikitravel.org/en/Main_Page
http://www.visitnorway.com/en/Articles/Norway/Fjord-Norway/Region-Stavanger/Tourist-information-in-Stavanger-and-Sandnes/
http://www.visitnorway.com/en/Articles/Norway/Fjord-Norway/Bergen/Tourist-information-for-Bergen/
You should also be aware that bus and boat are the only options for travel if you don't have a car. Trains don't run between these cities without going most of the way to Oslo and back. I recommend using the Fjord Tours site to plan your itinerary for trips around the various fjords. The prices they quote for the trip are just the actual travel costs using the recommended transportation, and timetables are accurate and helpful. Buses are regular in Norway and go to major tourist sites, but not very explanatory. Again, you will do much better to plan your routes ahead of time.
http://www.fjord-tours.com/default.asp
http://www.visitnorway.com/en/Stories/Getting-here-and-around/
http://www.nsb.no/?lang=en_US
http://www.rutebok.no/nriiis/Default.aspx
http://www.fjord1.no/en/