You can get to the city center from the airport by taxi, bus, and train. Details can be found here:
http://www.krakowairport.pl/en/60/4/176

Bus stations close to the conference center are at Czarnowiejska street (for 208 bus) and Mickiewicza avenue (AGH bus stop for 292 bus).

You can find the localization of the hotels and conference center on the map:
http://home.agh.edu.pl/~ppsn/data/hotels-map.pdf .

Map of the conference center neighborhood and communication between conference buildings:

Directions from U2 conference center to 429 Aula:

Outdoor track (blue line):
A. Leaving U2 (main conference building) turn left.
B. Turn right at the AGH Library.
C. Pass through the covered passage, turn left and enter C1 building.
Indoor track (orange line):
D. Turn right, go to the end of the corridor.
E. Take lift and go to the 4th floor (notice, that US 1st floor = Polish Groundfloor: 0). You will be in front of 429 Aula.

Map for tramways: http://www.mpk.krakow.pl/upload_i/mapki/tramwaje/tr_pdf_100828.pdf

Map for day buses: http://www.mpk.krakow.pl/upload_i/mapki/autobusy/ad_pdf_100828.pdf

Map for night buses: http://www.mpk.krakow.pl/upload_i/mapki/nocne/an_pdf_100821.pdf