Right across the street from the cathedral in Fredrikstad you'll find Hotel Fontenen. Very central, with good prices (for Norway).
A single room goes for 795 NKR (85 euro), a double 995 NKR.
Their style is that the guest should feel at home. For me a bit strange, since I'm staying at a hotel to see a new place...
But that's just me... :)
There should be internet access at the hotel, the dinner room seems to be very nice, as do the rooms.
I never stayed here, but passed outside. From the hotel it's a 100 meter walk down to the river and the long walk along there. It's also close to the shopping street, actually on the shopping street.
Directions: Look for the red cathedral. When you stand in front of it you have Hotel Fontenen behind you.
Nygaten 2 - 6, (formerly Radisson), Fredrikstad
Nygaardsgaten 9-11, Fredrikstad
Nygaardsgata 44 - 46, Fredrikstad
Turngaten 3, Fredrikstad
Latest Fredrikstad hotel reviews