In reply to francois:
I can't help with Västervik and other areas around Stockholm, but if you're driving from the UK or otherwise find yourself in the south, Kjugekull is around an hour's drive from Malmö and quite worthwhile. There's plenty of easier stuff right up to eights, a guidebook came out last year (available here -
http://kjugebeta.blogspot.co.uk/p/forare.html - or possible to buy in shops such as Naturkompaniet, which can be found in most major cities/shopping centres), and the setting is pretty great, being mostly within a beautiful forest.
The bouldering itself is quite varied, with a reasonable number of strong lines and nationally-known classics - there's a reasonable amount of info floating around on the net, and plenty of videos of the better known easier routes, such as this: There's at least one good campsite nearby, as well as the option to wildcamp legally, and the locals are all very friendly and happy to give advice/recommendations.
On the downside, however, the area has a reputation for being unbearably midge-ridden in the summer - I can't confirm it as I never bothered visiting outside of the winter months, but there are quite a few lakes in the area and so it seems pretty likely that it could be fairly unpleasant, not to mention crap conditions for serious bouldering. Could be worth a visit nonetheless if you're passing by (most likely if you're driving the E6 having come through Denmark), but I wouldn't plan to spend too long there in case it is unbearable!
Further to the north, Bohuslän (well-known within Sweden for trad) supposedly has quite good bouldering, and the crags at which the boulders are to be found are usually a lot more open than Kjuge. No idea about a guidebook, however, but you may well be able to dig up some information by rooting around.