There is a ferry going from kiel to Oslo
http://www.colorline.no/servlets/page?section=1000, it takes two nights I think, and is an even greater option, though you will miss Denmark. They have just gotten a brand new ship, a huge one. If you plan to go this route, try to allign your trip so that you get to travel on this boat.
As for hotels, evrything in Norway has high standards, even by european standards. You don't have to bring a tent, but remember that the many of the most inexpensive self catering cabins (the second cheapest after camping)do not provide linnen, so bring a sleeping bag or linnen.
Tenting in camp sites is a pain in the ass, litterally, as the ground is often really hard and uneven (not a lot of grass far north). Remember though that you can camp anywhere in Norway for free, even on private property. You must however bee atleast 150 meeters away from a house, worked garden or farmland, and not be of disturbance. Camping near a running brook in the wilderness is far more satisfying than in a camp sight, but do expect to have toturn off the main road to find a decent place... and a tent with a mosquito net is a must... and bring those eye covers that you get on the airplane... you can't distinguish night and day and sleep may get difficult.
I am not sure how expensive hotels get, but it will get expensive. I wouldn't worry too much about staying in the cheap places, it is not like you have to do this every night, and it is appart of the experience. You will meet travellers coming the other way, save some money, etc. No matter what you choose, it will be clean and safe! I just realised yesterday that I left one of my vintage scooters unlocked for a month, ready for someone to take it for a ride (I still advice people to lock their bike and hotelroom door, not every Norwegian is honest, but allmost).
As for tourguides, I am sure any will do. I know Lonely planet has editins for both Norway and the whole of scandinavia. I am sure iether will do... Norway is pretty straight forward and easy to travel. (Fixed prices on everything, everything works and arrives on time, clean and safe food no health or danger issues, everybody speeks english well, etc... in fact, it is strange that people die at all here...). A reference to costs, background informations, sights to see, refferences to accomodation and prices, are allways useful. The Norway specific guide will ofcourse be better, though I think as long as you have the general idea about things, have checked out the route you want to travel and the places to see, you just take as it comes... drive until you don't feel like it anymore, and then find a place to sleep.
http://shop.lonelyplanet.com/search_products.cfm?bNewSearch=t rue&searchfor=norway&select=javascript%3Avoid%280% 29
As for accomodation, you will come by them wherever you go... no worries here.
As for time, you can do it in a week, but you will be in a hurry. Two weeks is more appropriate, and a must if you calculate the return trip. A 250 kilometer trip in Norway will take approximatley 3-5 hours, icluding stops for food and gas. You might want to climb a glacier or something or spend the night in major towns rather than just pass through. And remember,unless you turn east into Russia, there is nothing beyond northerm Norway besided icy cold water,you have to calculate time to get back. You can either go by Hurtigruten, a luxury cruiseliner
http://www.hurtigruten.no/index.asp If you are on a budget, then this is definatley not an option. Your other options would either be to drive back through Sweden or Finland which is must faster as it is flatter (calculate 3 days). This stretch is looooooong and boring, with trees and more trees, and nothing to do or but drive.
And, don't even concider the North Western part of Russia, it is depressing as hell!
[This message has been edited by Wheelie (edited 01 December 2005).]