"Buy the book before the coin" is the most well-worn of numismatic clichés, but its truth still holds to this day; it always is beneficial to be knowledgeable about a numismatic object before buying it. Here is a list helpful books:

• A Guide Book of United States Coins, also known as the "Red Book" for its distinctive color, is a comprehensive catalog and price guide of all major U.S. coin types; it also includes sections on colonial and territorial coins, tokens and medals, and coins related to the United States. The "Red Book" is very helpful for the beginning collector, because, along with its valuations it includes grading tips and specifications. The prices, however, do not reflect up-to-date bullion values; the prices are only general ballpark figures. A Handbook of United States Coins is a similar book with a blue cover; the "Blue Book," as it is called, is not as useful for collectors looking to buy coins, and does not feature as much historical background and specifications as the "Red Book." Deep-dives which go beyond the information in the "Red Book" on certain series of U.S. coins are provided in Whitman Publishing's "Bowers Series."
• Cash In Your Coins: Selling the Rare Coins You've Inherited seems like a strange title to include in a list of books for coin collectors, but it provides very useful tips for the beginner looking to organize their collection, handle their coins, and sell work with dealers.
• A Guide Book of United States Paper Money is like the "Red Book" for paper money; it includes valuations and the historical background for each piece of paper money, from 3¢ Fractional Currency notes to $100,000 Gold Certificates.
• A Guide Book of United States Tokens and Medals provides an overview of the history behind a number of pieces in the collection of the American Numismatic Society. The book classifies tokens and medals in digestible sections, and provides plenty of historical background.
• Ancient Coin Collecting by Wayne G. Sayles is a great introduction to the world of Ancient Coins. While this book is not a price guide or catalog, its use lies in its historical background, lists of resources, and collecting suggestions.

If you want to browse before you buy, consider going to your public library and looking in and around Dewey Decimal 737.49. They're likely to have a few copies of the "Red Book" and perhaps a few others.

This list can be downloaded as a pdf file, here   >>Books to Buy<<