I went to Krakow for a mates stag weekend at the start of Feb. It was really good, so I can't remember that much of it! Its quite a weird place in that you see signs for pubs off the main square and they are through a doorway, down an alley and then up some stairs etc. We did spend the weekend fairly paranoid that we would wake up in an ice bath missing some vital organs after venturing into a pub/club we shouldn't.
One really good pub I can remember was CK Browar, its the pub with the biggest sign saying 'Pub' which sells beer in massive tubes of about 5 litres so you can just help yourself at your table. The prices seemed fairly reasonable aswell. Had some food in Roosters which was pretty good, the waitresses wore the tightest outfits! To be fair all the Polish girls were fit - they don't seem
to have an obiesity problem over there. The Irish Embassy is an irish sports bar which was quite a safe bet, but still a pretty decent pub. Most of the small pubs were alright and priced ok.
We struggled a bit with the clubs, went to a couple (can't remember their names though) and I'm sure we were fleeced in both of them (not badly, but just a little). There were no prices for drinks and I'm sure they take a look at you and then decide how much to charge you. It wasn't a rip off but just seemed a lot more expensive than the pubs. Apparantly the way around this is to ask for a drinks menu before ordering. Be careful with the clubs, we heard there was one which was more of a scam than a club which kept being shut down for ripping people off.
There was a good Gents club, which I also can't remember the name of above KFC - I know that description doesn't sound good but it was actually the best one by some distance.
I was surprised by how good the locals English was, better than than most of the Polish people I have met over here. A taxi from the airport to the main square was about 80 slotti for a car or about 130 slotti for an eight seater, you could even get the train in.
Enjoy your trip, it should be a good one!