How do you prevent the drum from jumping around?

When I put my washing machine on a normal cycle the drum moves around quite alot. I know that it needs to turn, but it looks like it has a wobble. (Almost like a hubcap that makes the wheel look like it is about to fall off) Then it makes these God awful noises, if you can imagine what an alien space ship sounds like, well it sounds as if it was landing in my kitchen! There are also little metal shaving on the floor after every wash, which leads me to believe that it must be making contact with metal. What do I need to do to rectify this from happening. Please help!