http://www.emulator-zone.com/doc.php/snes/
Snes9x works fine for me that link has the dl.
Once you have the emulator you need to download roms for the emulator. Just google something like (game name) SNES rom and it should pop up.
You can find package deals online that contain every SNES game ever made, roms anyways. I am not sure exactly sure where to download the package, but im sure its out there because my brother recently downloaded it for free.