How do I know if my power steering pump went out in my 1999 Grand Cherokee laredo?

Recently when I went to back out of my drive my steering became very rigid. When I forced the wheel over i hear a thud - my steering became very soft and everytime I tried to turn the wheel I heard a noise. When i looked under the hood there appeared to be a slight wobble in my power steering pulley and there appeared to be fluid everywhere (particularly on the under side of the engine). I looked in the reservior and it looked like chocolate pudding. Since I have to order this part without a refund I want to make certain that it is the pump and not another component.