If you like coins you're probably into observing them closely with a high-power magnifying glass, or a microscope. It's the best way to spot the top varieties, and it's fun. I like 14 power or better, with 10 power for general use.
I've also learned that when putting together numismatic publications, the bigger pictures are always much appreciated by collectors. This was the impetus behind my book, U.S. Coins Close Up: Tips to Identify Valuable Types and Varieties. It's based on a much earlier work of mine, Striking Impressions: A Visual Guide to Collecting U.S. Coins, which was, in turn, based on a weekly column called “Striking Impressions” that appeared in Numismatic News.
The idea, which is carried over in the current book, was to show varieties at great magnification. You can read about how to spot a variety or a diagnostic all day long, but if you can see a picture of it enlarged to the level of what see through a magnifying glass or a scope, it's much easier to learn what you need to spot.
So, U.S. Coins Close Up provides not only "close up" images of many top varieties but also a complete type guide for regular-issue U.S. coins minted up until 2012, when the book was published. Featured there are weights, measures, designers and a short history and description of each major type.
This book, which I hope you will find useful, can be purchased from ShopNumismaster.com for $6.99.