I think most Buddhist traditions are “non theistic.” This is different from atheism and theism, in that it essentially says “Even if God exists, God is mostly if not completely beside the point. The point is relying on yourself to save yourself.”
1. There are a lot of gods, as well as demons, etc. Typically the Sanskrit or Pali terms devas and asuras are used untranslated, in part because the ontological categories of different mythologies may not correspond exactly.
2. One of them was first and lives longer than the others. He says he's eternal and created everything else in the universe, but he's mistaken about both of those things.
3. The gods are better off than humans are, and they understand more than ordinary humans, but they still suffer and die; they all die every time the universe ends, which has happened many times.
4. So even the gods need to follow the path of awakening in order to end their suffering, which can lead to awareness that encompasses even the many creations and destructions of the whole universe. Some of the gods follow the Buddha for this reason.
5. But lots of people (and gods) have been able to observe some part of this picture and think they've seen the whole thing, which leads them to beliefs like monotheism, polytheism, atheism, or nihilism.
6. Thinking and debating about the gods and the nature of the universe is just a distraction from the meditation and awakening you need to end your own suffering.
The Tipitaka is much bigger than the small part I've read, so I don't know if I'm accurately representing what it says, and of course it's only one of many Buddhist canons. But I think the overall cosmology is not really a major point of disagreement between the different Buddhist traditions, especially because of point #6.
Still, I don't think it's accurate to describe Buddhism as nontheistic. If you think the devas aren't real you must think that the Tipitaka is at best an extremely unreliable guide to reality, at which point you're really just following whoever your personal guru is, not the teachings of Shakyamuni. Hopefully he's a good guru and not somebody like Baker-roshi.