Hi Heirah,
As Caroline mentioned, you can use an autoclave. If that is not available, you can also use a large pressure cooker of the type usually used for canning. As important as sterilizing your medium is the procedure for innoculating the medium. Ideally, transfer of the fungus to the medium occurs without introducing any mold spores or bacteria. This is best done by innoculating in the air stream of a HEPA filter. If that is not available, you can do the innoculation in a clean undisturbed room with still air.
I have used the "at home" procedures (pressure cooker and still room) to grow shiitakes. Other fungus, such as oyster mushrooms, grow very aggressively and sterile techniques are not as important. I have never tried to grow Turkey Tail fungus, so I am not sure how sensitive those are to contamination.
Turkey Tail fungus grows on dead hardwood trees. It will not grow well in soil. You can purchase Turkey Tail "kits" (pre sterilized and innoculated medium):
http://www2.mailordercentral.com/fungi/ ... ber=KTV100