There is basically just one cinema in Stavanger (well, there is another one in Sandnes, Stavanger's twin city) and it is located in the middle of town. There are 8 screens at the moment and screen number 5 is the best one (THX, DTS sound and the works).
If you want to check out what is playing go to www.kinoz.no and click on "Program Stavanger". Most of the information is in Norwegian of course but the movies are normally in the original language and subtitled into Norwegian. Prices vary from about 50 kroner (on Wednesdays) to 75/85 kroner other nights.
In the cinema you will find little shops where you can buy the stuff you need to see a movie (popcorn, soft drinks and so on :-). And if you are into coffee I would like to recommend enjoying the movie with a coffee mocca and a Stratos :-) (Stratos is a pretty good Norwegian milk chocolate by the way).