As you will soon see it could be a number of things, I suppose the favourites will be as already mentioned, wheel bearing the most common, followed by cv joint,
if the motor has lost a lot of oil though the swivel seal, that might lead you down a certain path, although a little gear oil will go a long way
its a case of jack the thing up and have a good look round, spinning the wheel and pulling on it with hands at top and bottom then at the sides, see where any movement is
if you are not sure what you are doing you can always to get someone local to help you, or try a garage to diagnose it, they wont charge for that (hopefully)