Belt problem...i think

I installed a new belt about a week ago and i was changing my oil when i noticed all this black soot like stuff all over wher the pulleys are.And when I start my car there is a rattling typer sound for a while or if it just idling.I have no idea why the black soot stuff looks like its from the belt, but the belt looks ok.What the hell could it be????:banghead:

Oh and 1 more question where is the fuel filter located and how do you change it (never did 1 before) i have a 99 2.2l cavy thanks