Im looking for recomendation - what should we visit, where eat, which hostel is good to stay in? We will have five days - is that plenty of time for visiting this city?
More than enough time, in fact so much time that you might want to think about a day trip to either Lublin or Krakow!
What to see? Depends when you'll be here.
As to where to eat, stay and drink, what kind of budget are you looking at?