A quick and dirty overview of each would be wonderful prior to jumping into the reading.
The Australian Aboriginal people tell stories about the Dreamtime: "This was way back, at the very beginning. The land and the people were created by the Spirits. They made the rivers the water holes the hills and the rocks and all the thing living. They gave us hunting things, they gave each tribe its land, they gave us our totems and they gave us our Dreaming."
These stories aren't religious as we understand Western, or even Eastern, religions. There's no worship involved, as such. There is certainly respect for the spirits of the dead ancestors, but not worship. There are no moral rules, no commandments, no spiritual goals. The Dreamtime stories are just explanations about how the ancient spirits and ancestors made the world.
Unfortunately, I can't recommend any specific reading. But, at least now you know what to look for: the Aboriginal Dreamtime.