I usually walk up to the bus station in the village nearby(Grace-Hollogne), bus #53 takes you to the St Lambert square(20 min ride), heart of town in which you can find a lot of cafes and such other places(Belgian beer!).
St Lambert square is also a central municipal bus station, from which you can take bus #1 or #4 to the central train station(Liege-Gullemins). From there on trains leave to Brussels, Brugge, Lux, Cologne etc...
Sucks that no one speaks(nor wishes or even tries)English.