As usual the rough guide offers more than bog standard tourist fodder, with very good sections on history, politics, arts and culture. However the places covered tend to be firmly on an established tourist trail. Great if you want churches and museums, but not so useful if you're looking for 'active' holidays in Norway's fine country and sea side.
Trekking doesn't have the coverage it has in other rough guides, and angling, a big draw for many visitors, gets hardly any mention. Flora and fauna together only get a couple of pages - Phil isn't really an outdoors person.
If you want camp sites these are better covered in free maps from Tourist Information (although i would strongly advise not relying on Tourist Information for much else, quality varies considerably) and bus and ferry times are more reliable from the web.
The guide does give a reasonable overview of what the general travel options are, perhaps the best around, but if you want more I suggest using the phone to contact rural hostels/hotels/campsites directly for relevant info on their areas. Or choose books from the 'Further reading' section and leave this one at home.