American Numismatic Association Grading Standards of United States Coins

Learn how to grade your U.S. coins quickly and accurately. Beginners, advanced collectors, and delaers will all find the text understandable and invaluable for grading coins. Every standard grade is illustrated and described in detail. Every coin is studied, from half cents to gold double eagles. Text descriptions of 30 levels help you pinpoint grades from poor to perfect Mint State. High-resolution photographs show you exactly what to look for. All 11 levels of Mint State are discussed in detail, as are Proof designations. A special 16-page full-color section highlights toning and other areas of interest.
The Official American Numismatic Association Grading Standards of United States Coins (Official American Numismatic Association Grading Standards for United States Coins)

PCGS Guide to Coin Grading and Counterfeit Detection

This book illustrates and explains with precise descriptions and digital images how you can determine the exact condition of a coin. Here is a coin grading volume so complete that—like its author, PCGS—it indeed sets the standard for grading coins. The standards for grading all United States coins, including precise definitions of Mint State and circulated grades. It encompasses grading standards of the Professional Coin Grading Service.
The Official Guide to Coin Grading and Counterfeit Detection, Edition #2