The "Certified USDA Organic" label indicates that the food was produced with no toxic or persistent pesticides or other environmentally unsound practices.
But other labels that might sound good can be virtually meaningless. Consider these:
The USDA certifies poultry and eggs (but not other meats) as free range, but its requirements are very loose. Unless the poultry and eggs are labeled "Organic," you can assume the birds have been fed foods that include growth hormones and synthetic pesticides.