Definition: The U.S. Coins Red Book, properly known as A Guide Book of United States Coins and published annually, is a widely-used retail price list for U.S. coinage. It is called the Red Book because of its red cover. The Red Book lists the values of practially every known U.S. coin ever minted, with most coins showing prices in several condition grades. 
See also: Book Review of the Red Book
See also: Book Review of the Red Book
Also Known As: A Guide Book of United States Coins by R.S. Yeoman; Edited by Kenneth Bressett; appx 400 pages (varies year to year), Published by Whitman.
Alternate Spellings: Redbook
Examples:
Most U.S. coin collectors and dealers consider the Red Book to be the "bible" of U.S. coin prices.