Oleśnica is a small town located in the close vicinity of Wrocław (30km). That is why You can get here without any problems from any place in Poland and not only. From Wrocław You can take 504 and 514 bus line ( direction: Wrocław – Oleśnica run by PKS POLBUS, ticket cost: 7zł, travel time around 1 hr), as well as by other long distance bus lines where Oleśnica is one of the stops on the way. Buses from Wrocław\to Wrocław, depending on the time of the day, run approximately every half an hour\hour. The Bus Station is located close to Brama Wrocławska (Wrocław Gate) leading to Oleśnica Market Square.
Oleśnica has also two railway stations: Oleśnica and Oleśnica Rataje which provide convenient connections to Wrocław and other places as well. More info and time table: http://rozkład.pkp.pl