American Humanist Association One of the oldest and most democratically run groups in the non-believer community. AHA has a number of local chapters (including the Humanist Action League). They also host a great convention each year.
Americans United for Separation of Church and State One of the best advocacy groups working in the religious liberty field. They conduct information, legal and lobbying campaigns. They also support create and support local groups. Their web site has some great audio recordings.
Atheist Alliance Atheist Alliance International (AAI) is an organization of independent religion-free groups and individuals in the United States and around the world. Their primary goals are to help democratic, atheistic societies become established and grow and to work in coalitions with like-minded groups to advance rational thinking through educational processes.
Camp Quest The first Secular Humanist Camp for Kids.
Campus Freethought Alliance The Campus Freethought Alliance links freethinkers and atheists on campuses around the world.
Celebrity Atheist List A surprisingly large collection of non-believing celebrities.
Center for Inquiry Promotes and defends reason, science, and freedom of inquiry in all areas of human endeavor.
Center for Inquiry - West The new West Coast branch of the Center for Inquiry.
Council for Secular Humanism The Council for Secular Humanism is North America's leading organization for non-religious people.
EvolveFISH The best supplier of humanist, freethought and atheist books, Darwin Fish emblems and other products on the web!
Freethinkers of Colorado Springs HAL's sister organization in Colorado Springs.
Freethought Radio A bold attempt to operate a full time Freethought radio broadcast-type web site. They have some excellent material.
Gay and Lesbian Atheists and Humanists Gay and Lesbian Atheists and Humanists is an organization with four main goals:
1. Support equal rights for lesbians, gays, transgenders, and bisexuals.
2. Educate people about atheism and humanism.
3. Support separation of church and state.
4. Provide freethinkers with opportunities to get to know each other.
The Humanist With a distinguished cadre of feature writers covering everything from science and religion to politics and popular culture, and with a wide-ranging list of stellar contributors, The Humanist continues to challenge its readers with insightful ethical critique and commentary on the central issues of our time.
Humanists of Colorado Striving for justice; advocating democratic principles; promoting human rights; eliminating wars, promoting peace; and promoting the wise use of science and technology.
National Center for Science Education A national advocacy group that promotes science education.
Pascal's Wager Pascal's Wager is well-known to many atheists. On the Internet, it is probably the most common argument heard from Christians, and the regulars of newsgroups such as alt.atheism feel cheated if a week goes by without someone bringing it up (this rarely happens), only to be shot down in flames (this always happens). Pascal's Wager is quite simple, and superficially appears to be a strong and compelling argument for theism. However, a little close scrutiny soon reveals the flawed logic and reasoning behind it, which actually makes it one of the weakest arguments a theist could come up with.
The Secular Web One of the best web site for reading Freethought material.
The Liberal Store A source for wearable items to promote liberal ideas.
The Skeptics Dictionary An alphabetical index to pseudo-science, superstition and fallacy, from Abracadabra to Zombies.