There are several possibilities i.e., inner or outer tie rods ends, wheel bearings, ball joints, loose spindle nut. So, since its better to be able to look at this in order to accurately diagnose it, I'm going to suggest that you call a couple of your local alignment shops to see if they give FREE front end inspections. If they do have them to diagnose the problem, but DON"T BUY ANYTHING until after you have posted their findings here. Perhaps we can assist you in repairing the problem yourself (if you are so inclined).
i don't necessarily like telling you to take the car to a shop (because I know you can do that without my help I just figured you wanted to repair it yourself), but sometimes this will save time and money {avoid replacing parts hoping to eventually find the right one--this is one of those nice shortcuts}.