INFORMATION

CURRENCY

The US dollar is divided into 100 cents.
The coins in use are 1 cent (penny), 5 cents (nickel), 10 cents (dime), 25 cents (quarter), 50 cents (half dollar), 1 dollar (the latter two are not very common).
The banknotes are 1 dollar (usually called single), 2 (rare to find), 5, 10, 20, 50, 100.
The dollar is also called, in slang language, buck. The United States Mint produces the coins while the Bureau of Engraving and Printing prints the banknotes.
In recent years, new 5, 10, 20, 50 and 100 dollar banknotes have been produced to counter the phenomenon of counterfeiting.

References

United States dollar (Wikipedia)
U.S. Currency (Bureau of Engraving and Printing)

Useful links

Coins and Currency (Department of the Treasury)
U.S. Currency Education Program