Can not play movies

Hi, Can anybody tell me how to play movies (VCD, mpeg, avi etc) in SuSE 10.1. I have tried the usual players that come with suse installation, but they are throwing different errors. Most of them are codec oriented. I don't know how to get a codec from net or install that. I am quite new with Linux, so please explain as much as possible. Or give me a pointer to any online material. Thanks in advance. Bikram Chatterjee