Two months ago I was in Kraków for seven days, and on two of those days I hired two local guides who I feel are excellent, and I highly recommend them.
The day after I arrived in Kraków I hired local guide Renata Guzera for an introductory four hour walking tour of Wawel Hill, the Old Town, and the Main Market Square. And Renata was absolutely great. Along with describing the various sights in great detail Renata is also very friendly and engaging, and she was also quite open in regards to our walking tour itinerary - she was very flexible on what I wanted to see.
If you're interested in hiring Renata to show you around Kraków, here's her website (which also contains her prices and contact details)...
http://www.cracowguidetour.com/
On another day I hired another local guide, Janina of Krakuska Kraków City Guide, and on this day I hired Janina on a five hour tour of Kazimierz (the Jewish District) and Podgórze, with a visit to the Oskar Schindler Factory Museum. Janina was also very flexible on the sights I wanted to see, and she was very open with her recommendations as well. And just like Renata, Janina is also very friendly and engaging as well.
Janina is on maternity leave right now, though I believe she may start leading walking tours again by the Spring or early Summer. If you're planning a trip to Kraków in the Spring or Summer of 2016, Janina is another local guide I highly recommend. Here's the link to her public Facebook page for her freelance tour guiding work...
https://www.facebook.com/krakuska.krakow.guide/timeline?ref=page_internal
I absolutely enjoyed the walking tours I went on with Renata Guzera and Janina. Exploring Kraków with these two exceptional and excellent guides was just like exploring Kraków with two local friends. :-)