Some great information about federal food stamps program published by the Congressional Budget Office:
Supplemental Nutrition Assistance Program

SNAP spending and participation reached record levels in 2011. Nearly 45 million recipients, one out of every seven U.S. residents, received SNAP benefits in an average month in fiscal year 2011. Total federal spending for the program was $78 billion.

To put it in context of daily life:
Average Adjusted Benefit Per Person Per Day (inflation adjusted dollars):

$2.49 in 1980
$2.71 in 1990
$2.67 in 2000
$3.97 in 2010

They also published another report that looked at policy options:
Policy Options