There are more than 100 hostels in Kraków now, so just have a look yourself:
If you need a map of Kraków take Mr Gordonski's CitySpy Map. It also contains useful informations about things to do. Another good source of information is Kraków In Your Pocket.
As not everybody is speaking English in Poland and as you don't want to feel stupid by not even knowing how to say 'Hello' in Polish, print yourself a copy of the Pocket Talk English - Polish micro dictionary.