Atheism is simply the lack of belief in God or gods (and nothing more than that). We are unconvinced by all the evidence that we have seen (and we've actively looked at the claims.) Faith is just belief without evidence and it's nothing more than gullibility.
Many atheists are Humanists, which is a philosophy of life based on reason. For more on humanism, you can look at http://www.americanhumanist.org/ or http://www.secularhumanism.org/.
Note that http://www.humanism.org/ and other sites that you might stumble across are a misrepresentation of Humanism created to deceive believers (i.e. the gullible).