Is There A Book Or Guide To Grading Coins, By The NGC Or PCGS?

For US coins, I use James Ruddy's Photograde: Official Photographic Grading Guide for United States coins.

PCGS has Photograde Online to help with grading on your own

The PCGS Photograde is nice, but it has several limitations:

1. There are no descriptions as to what is expected in a certain grade level, so it makes telling the difference between grade levels difficult sometimes. The ANA grading standards gives this information.

2. Photograde does not take strike weakness or design modifications into consideration, so a higher-grade coin could look worse than a lower grade coin. Having text descriptions helps with this.

However, Photograde is useful for determining the differences in between uncirculated grades. The concept of eye appeal and the number of contact marks is better described woth high-quality images than just text descriptions.

The previous posts give the best books on the subject, imo. That said, really the only way to truly learn is to closely examine already graded coins (stick to PCGS and NGC for the most consistency and accuracy) in a given series over and over until you start being able to get a sense for what the market grades those coins at.

That said, the books are a great place to start because they'll help you learn what to look for. Circulated coins tend to be easier to learn from the books, whereas uncirculated is a bit tougher and definitely takes more hands on experience and exposure. It may be frustrating early on, but it is a worthwhile endeavor, as even the big 2 (PCGS and NGC) get it wrong sometimes.