The slang "buck" or "bucks" when referring to money is so common-place that no-one really questions it’s oddity. But it turns out that the word "buck" is short for "buck-skin" (from a deer). Buck-skin’s were used as currency once upon a time.
The term "bread" has an origin from the United Kingdom. Specifically the Cockney phrase for money is "bread and honey" which was eventually truncated to just "bread".
With regard to the $ symbol, seemingly the most popular theory as to it’s origin is that it was created through the superimposition of the initials of "United States" (U and S) on top of each other. So Imagine an "S" with a "U" written right on top of it. The theory suggests that the bottom loop of the "U" was eventually lopped off to give us the more familiar "II".