In reply to longol:
Matt and Rog seem to have it pretty well covered, the only thing I would add is check out the Bergen Climbing club website (some of its in English and google translate does a reasonable job on the bits that aren't)
They have the option to get a digital version of the guide book for £10 which is pretty good value and its nice to support the locals http://www.bergen-klatreklubb.no/englishinfo.php
If you can get access to anyone with a car then I would suggest Gjorkeride
or the other crags on the island of Sotra, they are great. Really nice climbing, well bolted, west facing (evening sun) and just very pleasant.
Also not mentioned above is that there are some good walls in Bergen if its raining (which it does occasionally). There is one at Bergenshallen (where all the cool kids hang out, quite hard) also just down the road is one at the student hall (Fantoft) and there is also a nice one in the NW of the city called Lemkulen. For any of these you will need to pass a test (Brattkort) which involves being patronised by a kid who will tell you you can't belay properly, but it only lasts about about 15 mins and then you are free to climb in any of the walls.