Oldie but Goodie From shadowstats.com

Hyperinflation Special Report
Shadow Government Statistics (8 Apr 08)

Excerpt: “Howard J. Ruff, who has been writing about these problems and issues since Nixon closed the Gold window, rightly argues that it will take some time for a barter system to be established, and suggests that individuals should build up a six-month store of goods to cover themselves and their families in the difficult times.”

I would note that I generally recommend 1-2 years inventory of non-perishable goods.  ~ Catherine