Go down to your local tire store and they will give you all the old tires you want for free. Drill holes half way around one half of the tire (in tread & sidewall), then put 3 or 4 screws through the tread (all the way to the inside of tire by 1 or 2") on the other half of the tire at the midway point. The half with the screws pour some quick crete and add a little water. Let it set, the screws will hold it in place. Then drop them in shallow water, but deep enough that the tires are submerged. The fatheads will spawn inside the tires (their eggs need something to float up to and attach)and it will offer some cover to protect them.
If your pond is not full, I have a better way, see the section here under "habitat"