you may also want to pick up one of those valve things that adjusts the airflow. mine lets me hook up 2 filters to one pump.
One of these things:
Do you see the "nipple" on the image above? you attach the tubing FROM the pump into that. And you see the tip of the black nozzles? You attach another peice of tubing into one or both of those. The Tubing from the black nozzles wll attach directly into another "nipple" that will be on the sponge filter (in the top pic, its inside the plastic tube where the bubbles come from).
So - one line of tubing goes from airpump to the black valves. Another peice of tubing goes from the black nozzle into the airpump. And thats it.
you can kind of see the airpumps in here along with the tubes...sort of.