There is an expression in coin collecting that encourages collectors to “buy the book before you buy the coin.” This is excellent advice as many coins have variations, and minor or major markings which can impact value within the same series and sometimes the same date and denomination. Education is key when buying or selling collectibles. And, even though you are reading this post on the internet (my website), not all the information you can learn from books and years of hands-on experience with coins can be found online.
When I first started getting serious about coin collecting I bought A Guide Book of United States Coins. It is available in many book stores, coins shops and online in hardback, spiral-bound and large print. Published annually, it includes details about all U.S. coinage from pre-colonial to modern. Today I have more than 50 books in my numismatic library and subscribe to two different price guides.
At the end of the day I feel confident I can answer most questions about U.S. coinage because of the reading and research I have done but if I cannot, I most likely own a book with the answer. Happy Collecting!
Source: “Personal reading” and www.coins.about.com