What are the teachings of Atheism?

Answer 1

Answer
As stated previously there is no organized belief system. Atheists are largely independent (free thinkers) and there is not strong organization although there are a few groups. Answer
Atheism is not an organized belief system - indeed it rejects faith as as useful way of understanding; it has no teachings.
To assume that atheists have common beliefs is to misunderstand what atheism is. Atheists simply don't hold a belief in god(s). That is all. Atheists reject faith-based belief and instead tend to rely on empirical (testable, repeatable) evidence.
Answer

The above is correct. Atheism has no teachings: it is simply the position which reasonable people take when confronted by religion. Atheists assume nothing. There are good atheists and bad atheists. But the only thing which could be said to be a "teaching" would be this: "don't believe what anyone tells you without checking the facts and thinking about it for yourself." That's it. if you do that, and you do it thoroughly, then you'll be an atheist.
Whatever else you are is up to you.

Answer

As noted before, atheism is not an organized belief system and has no teachings; however, in general, atheists would agree with the principles of secular Humanism.

Note: atheist does not = secular humanist