These resources will help you get up to speed quickly.

Free Geiger Counter Use Guide.

http://technologypals.com.au/wp-content/uploads/2012/03/Using-a-Geiger-Counter-to-test-food-for-Radioactive-Contamination.pdf

DIY Food testing lab Guide

http://technologypals.com.au/wp-content/uploads/2012/06/How-to-set-up-a-home-or-community-food-testing-lab-for-radioactive-contamination.pdf

"The Food Lab", has a list of the latest international reports of food contamination,

http://sccc.org.au/archives/2861

Here is an International list of Radiation monitoring stations.

http://sccc.org.au/international-radiation-monitoring-stations