Now it's time to dive in with some specifics, right? I'm tiring myself, and I don't know if anyone's bothering to read this anymore, if indeed anyone ever was. Well, one last semi-generalized note, actually.
Not everyone agrees on this, but it's my own personal opinion that chapter one is intended to be poetic. In many ways it's very poetic in form and feeling, and as such, I don't think it's necessarily intended to be taken as literal. The real point behind this chapter is the creative power of God, not the specific fine detail regarding what He does with it. That said, I do think one can take this chapter in a fairly straightforward way nonetheless, and a rule of thumb for Bible understanding is that if you can find a way to interpret it non-symbolically that makes sense, you should probably go with that.
The main thing that is taken as poetic by many is the concept of seven "days". Is a day 24 literal hours? Well, who knows? In a sense, a "day" is the period of time it takes for the earth to rotate 360 degrees relative to the sun's position, but of course the sun wasn't created until day four, so what does "day" mean in a more practical sense for those first three "days"? Who knows, indeed. I reiterate that the Bible is not a science textbook, and the technical specifics of the creation are not the real point of the story anyway.
On day one, God creates light. The skeptic says, "But if there's no sun, how can there be light? This doesn't follow our scientific understanding of the order things were created!" Point one: the sun is hardly the only possible light source in the universe. Point two: I'm not a physicist, but I believe that in fact this does follow the current scientific understanding.
What does science say presently about how the universe began? In the beginning, there was nothing; and by "nothing" we mean that not even time or space existed. You could say that it was "without form, and void". Then, all at once, there was something! What was that something? Essentially, it was a tiny little ball of energy, which exploded and made everything in the universe over the course of an extended period of time, supposedly over 10 billion years. At first, this ball of energy was so hot and charged up with power that it was unable to condense into matter of any recognizable form, but it surely radiated off one thing: light, and plenty of it. To say that light was the first thing created in the universe is, I would say, the one thing in this chapter that precisely matches up with modern scientific understanding. But I don't want to lose sight of my repeated warning that we're not really talking science here. The Bible doesn't say where this light is coming from, so we either speculate, or we let scientists figure it out.
On the poetic side again, the "light" may be a very symbolic thing. While I could speculate on how "God divided the light from the darkness" is flowery talk about how eventually that proto-plasma (Is that a word? I don't know what to call it.) at the beginning of the universe eventually cooled enough to settle into clumps of gas separated by empty space, I think it's much more worthwhile to talk about the imagery of light vs. darkness that pervades the Bible from beginning to end.
There's a fairly common belief known as "gap theory" that speculates on why God would create the heavens and the earth "without form, and void". (Once again, I think this shows a misunderstanding of the sequence of events; verse one is not an event so much as a "thesis statement," if you will, of the story that follows.) That theory is concerned with a pre-history that supposedly occurs in a gap between verses one and two. I don't know it well, but I believe the idea is that God made the universe in verse one, something went wrong that was somehow related to an angelic rebellion led by Satan, and the upshot is that God had to wipe everything out and start over: verse two.
Whether you choose to interpret things that way (and it's quite a bit of a stretch, clearly) or not, it's compelling to think of God creating a world which he infuses with "light" (goodness) so that he can separate and drive away "darkness" (evil). Really, that's what the Bible as a whole is about, so putting it right there at the beginning is interesting. As I have heard many a pastor say, while we tend to see the "day" starting with light and ending in darkness, the Jewish reckoning is that the "day" begins at sundown, thus starting with darkness and leading to light.