There are several useful books and supplies that you should consider when collecting half cents or large cents. You have heard it before: Buy the book before you buy the coin!
Half Cent Books
There are two books that I use regularly for half cents, and they are:
"American Half Cents: The Little Half Sisters", Second Edition, Roger S. Cohen, Jr., yellow hardback, copyright 1982. This is the book that helps you attribute the half cent varieties by Cohen number, and it includes lots of photographs and descriptions. In my opinion, this is the standard reference for half cents. You can still find these at coin shows and on ebay: a new copy is around $80 - $100, and used copies are usually $50 - $75. If I have any copies available for sale at this time, you will find them on the EVERYTHING ELSE page;
"The Half Cent Die State Book 1793-1857," Ronald P. Manley, Ph.D., brown hardback, copyright 1998. This book has updated rarity information as well as photos of almost every recorded die state for each half cent variety. The last time I checked, these were $75 new, and if you are lucky, you can buy one that has been signed by the author. If I have any copies available for sale at this time, you will find them on the EVERYTHING ELSE page;
Walter Breen also has a half cent encyclopedia that was published years ago. That book has a wealth of great information, but I typically use mine only as a supplement and not as a daily reference. I think that book is certainly worth the money though, and it does have a lot of meat-and-potatoes reading material within it's covers.
Large Cent Books
There are several different books available for large cents, but in my opinion, there are two that are absolutely a must-have for the early- or middle-date enthusiast, and they are the two-volume set by Bill Noyes:
"United States Large Cents 1793-1814," William C. Noyes, green hardback, copyright 1991.
"United States Large Cents 1816-1839," William C. Noyes, maroon hardback, copyright 1991.
These come in a two-volume set, and you can typically find them on ebay or at coin shows. New sets used to sell for $250, but they are nearly completely sold out now, and the current price is $350 for a new set. Unfortunately, it is almost impossible to find used copies. If I have any of these available for sale at this time, you will find them on the EVERYTHING ELSE page.
"The Cent Book 1816-1839," John D. Wright, white hardback, copyright 1992. This is an alternative to the Noyes middle date book listed above, and if you are a middle date collector, you will want BOTH books. According to John and Mabel Ann Wright, there are still some new copies available at $100 postpaid. You can purchase these directly from the author at:
John D. Wright
1468 Timberlane Drive
St. Joseph, MI 49085
"The Die Varieties of United States Large Cents 1840-1857," by John R. Grellman, Jr., brown hardback, copyright 2001. This is THE book for late date large cents, and it is available for $100 postpaid directly from the author at:
P.O. Box 161055
Altamonte Springs, FL 32716-1055
(407) 682-9592 or (407) 221-1654
The standard price guide for all US half cents and large cents is "Copper Quotes by Robinson," commonly referred to as "CQR." This work is published by Jack H. Robinson with collaboration from dozens of EAC dealers and collectors. The last edition was issued on 04/30/11 at EAC Portland, and they are $50.00 postpaid. I should have some of these for sale in the EVERYTHING ELSE section.
I also recommend that you purchase at least a 5X magnifying glass. I like the cheap, black pull-out style because they are cheap and easy to carry in your pocket at shows. You should look at EVERY coin with a 5X glass to make sure that you spot every defect before you make a purchase decision. This process will also help you identify fakes as well as make or confirm a variety attribution. These can be purchased at most coin shows, on ebay, or at any of the online coin suppliers. In addition to the cheap model that I like, there are also dozens of more expensive versions, including durable metal constructions and those with multiple zoom powers. But whatever style you choose, make sure that you own at least ONE of these that is a 5X!