Poland is an odd, but interesting place. Its probably better during the warmer season, but Hel on the Baltic coast is an interesting day trip worth taking I think. Pretty cool night-life there. If youre looking for romantic places, check out Kazimierz. Theres no train to get there, but if you can make it there its worth it. In Krakow, specifically, eat at Kuchnia U Doroty for real Polish food. Also, theres no better place to work up an appetite than Auschwitz. If Nazi concentration camps arent your thing, old town is a great spot to check things out. Neat little shops and restaurants. The worst possible aspect of Poland the time of year you are going is the pollution. Its god awful in the Winter.