There is no humanist catechism. There are the Humanist Manifestos, but that is no dogma. Humanists as the local level have tried to define what is important to them. Here are some experiments.

"Since the earliest days of philosophic reflection in ancient times in both East and West, thinkers of depth and acumen have advanced the single proposition that the chief end of human life is to work for the happiness of man upon this earth and within the confines of Nature that is his home. This philosophy of enjoying, developing, and making available to everyone the abundant material, cultural, and spiritual goods of this natural world is profound in its implications, yet easy to understand and congenial to common sense. This man centered theory of life has remained relatively unheeded during long periods of history. While it has gone under a variety of names, it is a philosophy that I believe is most accurately described as humanism."

From Corliss Lamont: The Philosophy of Humanism.

Here's what they say:

Atheist: There is no god.
Theist: Oh, yes there is.
Polytheist: There are lots of them.
Pantheist: They're everywhere - in trees, music, people.
Agnostic: You can never really tell if they exist.
Ignostic: Who cares? God and evil are real - and human
Humanist: We're human, so let assume people matter most
Freethinker: What matters is freedom to keep asking questions

From Contact! the newsletter of the Humanist Fellowship of San Diego.