Those are the nuts and bolts that the average Christian is struggling with in the middle of the evolution/creationism debate.
What does it all mean?
If we view Genesis as the best explanation offered to us by people who sought to explain God, Humanity, and their relationship to each other...there is still much value to be found in Genesis.
If we view Genesis as historical fact given to Moses in a vision, or in a direct, fireside chat with God....then it's hard not to be a YEC-er.
The outcome is determined by what we believe Scripture is and what its purpose is. I won't trot out the whole inerrancy argument, because I've already given my opinion pretty extensively on that subject in the past.
In the past, I used to read Genesis 1 and think,"Wow...that's really close to the concepts of the Big Bang and evolution." God creates the earth and heavens out of a primordial mess. He commands the water, earth and sky to be formed. He commands the land to produce vegetation...and it does. He commands the waters and land to produce living creatures....and they do. The last thing created and made is man....the most advanced creature produced by the evolutionary process.
It's not hard to draw parallels between the creation story and evolution. In fact, compared to other creation stories, Genesis 1 seems downright scientific; that is until you realize that Day 3 has the land being covered with vegetation before the sun is formed on Day 4. That throws a wrench into any idea that Genesis 1 is an inspired revelation of evolution taking place.
No sun=no plants.
If we place ourselves in the sandals of the ancients thousands of years ago, observing the world, nature, and life...we just might be able to understand Genesis a little better.
Think about the descriptions offered in Genesis 1. Distinctions are made between water, earth and sky. Those are pretty basic, observable categories. Most animals fall into one of those categories...except for maybe amphibians which could be water or earth creatures. Distinctions are made about plants and animals reproducing according to their own kind. What person has ever planted a peach pit and grown a pine tree? What cow has ever given birth to a sheep?
These are observable demarcations, even to the ancients, that are being put into use to explain the order of the cosmos. I would go so far as to say that the descriptions are "scientific" in their attempt to take what was observable and form a theory of creation from it. It's no coincidence that livestock aren't created until the land is covered with vegetation. What would they have eaten? Wild animals aren't created until there are birds and fish to munch on.
And then...at the end of the creation narrative...we have man's creation. Man is made to rule over the other animals. He is said to be made in the image of God. He is created male and female.
This is more general observation. Humans sense that they have something which other animals don't. They see that they have the power to shape and control nature and animals. They see that they are wholly "other" throughout the earth; somehow better, somehow more powerful.
This is what being made in the "image of God" is about.
Genesis 1 is "true"...without necessarily being "factual".