From Wikipedia (see: http://en.wikipedia.org/wiki/Secular_humanism):
The philosophy or life stance secular humanism (alternatively known by some adherents as Humanism, specifically with a capital H to distinguish it from other forms of humanism) embraces human reason, ethics, social justice and philosophical naturalism, while specifically rejecting religious dogma, supernaturalism, pseudoscience or superstition as the basis of morality and decision making.
It posits that human beings are capable of being ethical and moral without religion or a god. It does not, however, assume that humans are either inherently evil or innately good, nor does it present humans as being superior to nature. Rather, the humanist life stance emphasizes the unique responsibility facing humanity and the ethical consequences of human decisions. Fundamental to the concept of secular humanism is the strongly held viewpoint that ideology—be it religious or political—must be thoroughly examined by each individual and not simply accepted or rejected on faith. Along with this, an essential part of secular humanism is a continually adapting search for truth, primarily through science and philosophy. Many Humanists derive their moral codes from a philosophy of utilitarianism, ethical naturalism or evolutionary ethics, and some advocate a science of morality.
The following links tend to fall within the definition above.