There are plenty of train and coach connections to other cities (domestic and international). The train station is a 7 min walk from the main square (and is right next to a huge shopping mall). The coach station is a short (2-3min) walk from the train station, just behind it.
The Krakow Coach Station (also known as the Krakow Bus Station, but it is only for coaches) is known as the MDA Coach Station. (It used to be called the RDA station).
You can find a small restaurant/cafe, ATM machine etc.
Find their official website here.
Tip: Inside the coach station ticket area/waiting area there is a big board of coach times. Often these only show DOMESTIC coaches, and not international ones. Be sure to ask someone who works there if you cannot find your coach!
The train station in Kraków is called 'Kraków Główny'. It is located right next to the Galeria Krakowska Shopping Mall, and is about 5-10 min walk from the old town area.
Find the official website here.
Read about exploring the abandoned Liban Quarry (and ex Nazi labour work camp)