Oslo (Vålerenga plus others)

Getting there
Ryanair - Stansted and Prestwick to Oslo Torp (2 hours by coach from Oslo)
Norwegian - Stansted to Oslo
British Airways - Manchester to Oslo
WhichBudget - to check out all the options
There's a connecting bus service for all Ryanair flights into Torp. The bad news is that it costs about 9 quid each way. There's a direct train service from Oslo airport into the city, but it's about 13 quid each way; alternatively there's the normal train service (about 7 quid each way I think) or the bus (£12.50 return) which takes 35-40 minutes.

Guides & info
David M (Toon fan) guide
Rough Guides (select Oslo from 'Featured Cities')
Backpackers Guide
Oslo city info
Public transport
Torp airport

It's possible to get a double room in a 3 star hotel for about 65 quid a night. One and two star hotels must be cheaper, if only I could find any that can be booked on-line!
Anker Hostel (cheap, but basic and in a pretty crap location)

Anker (on-line booking)
Perminalen (30 quid per person in a twin, 26 in a triple)
City Hotel (a bit more up-market)
Octopus (hotel booking site)

(Current exchange rate is about 11.3 kr to the pound)

As well as being Vålerenga's ground and the National Stadium, Ullevaal Stadion is also the home of Lyn Oslo. Not surprisingly the two clubs get easily their biggest crowds when they play each other. It looks a very tidy ground, very much like Basel's in fact, with a capacity of 25,000. It's quite a way out of town, about 4 miles from the centre. However there's a fast (10 minutes) and frequent (about every 7-8 minutes) tram service. You get number 4 or 5 I think.
Official Vålerenga site (not much use though unless you speak Norwegian)
Ullevaal Stadion (gives you a good idea what the ground's like)