Instructions
Buy books about coin grading. Online marketplaces will give you the widest choice, and these books contain information and advice about learning how to grade coins, as well as photographic examples of what to look for in each grading step.
Visit specialized websites such as the Canadian Coin Certification Service, the International Coin Certification Service, and the Professional Coin Grading Service for expert advice and useful industry contacts to have as you learn the trade.
Watch an expert at work grading coins at your local antiques store. Even after reading all the books and looking at pictures of coins of particular grades, it is still beneficial to watch a real expert and learn the subtle nuances that make the difference between, for example, perfect mint-condition coins and typical mint-condition coins.
Depending on the state of the coin, you will grade it, according to the scale, with a letter and number combination that correlates to the condition of the coin. The grading scale can be found in the resource section of this article.