This is the second part of an attempt to define a core set of books that any Atheist, or anyone who wishes to know what Atheism is about, should read and have in his or her library.
There are, and have been for 2,000 years and more, quite a few Atheists writing on the subject. Of course the frequency of published views is far greater in the 19th and 20th Centuries, since by then the Catholic and Protestant churches had stopped torturing and killing Atheists and other heretics.
There are some very good anthologies of Atheist writings spanning two millennia. The selections are extended extracts of articles and books, not just brief quotations. This not only lets us trace Atheist thinking through the centuries, but also lets us see argumentation at the deepest theological and philosophical levels. This is in contrast to the popular writings of the New Atheists, who generally argue at the level of understanding of a well-informed lay person.
The Portable Atheist, edited by Christopher Hitchens, presents 47 selections from about 60 BCE up to the current decade. Each selection is prefaced by biographical details and some historical context. This book is actually indexed, and has a bibliography.
Atheism: A Reader and The Agnostic Reader, both edited by S. T. Joshi, also are collections of several dozen longer selections, again prefixed with short biographies. Both volumes list books for further reading.
Although there is some overlap in the writers who are represented in the three volumes, there is less overlap in the actual selections. All three of these volumes are well worth reading.
Western Atheism: A Short History, by James Thrower, is a quick overview of atheism in three periods: antiquity, the Middle Ages, and the Enlightenment to the present. Read this book to learn how, and in what context, people have struggled to hold and express Atheist ideas.
Freethinkers: A History of American Secularism, by Susan Jacoby, is a fascinating account of the struggles and triumphs of the many Americans who have fought to defend our secular heritage.