I'm going on Saturday for five days & haven't really thought about it yet - two questions:
a) What am I likely to forget? I need to check in online at some point. I need to find my passport. I can change currency when I get there, right?
b) Is there anywhere I definitely need to visit? I'm flying to Katowice, so will probably base myself in Krakow. What's there that I need to see? I'm planning a daytrip to Auschwitz - is there anything else interesting nearby or in the city itself?