i was in Kraków once, i can recommend the kiełbasa and oscypek from the main square, ice cream in the italian lody cafe in Galeria krakowska and the walking tours around the city. 

I went on the Schindlers list walking tour and the communist walking tour. These walking tours are great because you get to see historical places and have them explained to you. We went to on the communist tour to Nowa Huta, our guide was from their and she gave us many insights into the place. She also took us to a coffee shop where we were shown a film about the area.

the one thing i didn't like so much was that i couldn't practice my poor polish because many poles in this city have excellent english