Reinstall OS X Snow Leopard on a 2011 MacBook Pro
According to this KB document:
http://support.apple.com/kb/ht1159

MacBook Pro (Early 2011) requires at least OS X 10.6.6, so the disc you ordered (10.6.3) does not work on your unit as it does not contain the required drivers.

Solutions:
1. You can bring your MBP to a nearby Genius Bar for reinstall, or;
2. Find a older Mac that is supported by your install disc, put your MBP into target disk mode. Run installer on that older computer and install to your target-disk-mode MBP . Once you complete software updates to 10.6.8, your MBP should be bootable again.

I suggest you get Lion so that you may use Internet recovery in the future:
http://support.apple.com/kb/ht4904