"The boys are eating some good bread."
Translation:Les garçons mangent du bon pain.
Basically, 90% of adjectives are placed after the noun, in French.
With this link, you will know more about exceptions: http://french.about.com/od/grammar/a/adjectives_4.htm
Aren't there (sorry if I'm wrong) exceptions for BAGS (Adjectives that describe beauty, age, goodness, and size) <--- these would go in front of the noun instead of behind?... mah X_X
Don't trust me ||D I have a B in French class
It has to do with literal vs. figurative. Figurative is before the noun and literal is after to help distinguish meaning. In this example, the bread is good, but it does not literally have a "good" trait like people do. Apples are literally red so rouge goes after pomme. It's easy once you understand the logic behind the placement of adjectives.
When the adjective comes before the noun, doesn't the du change back to de ?