It's DC. That means you have to start with Superman, Batman, and Wonder Woman. It's just the way it is. Even though Green Lantern has, I think, eclipsed Wonder Woman in the popular culture at the moment (incoming movie vs failed TV pilot), she's still one of the Big Three and thus gets prime of place.
Because the Trinity are pretty much the core of the DC universe, we need to start with them. Once they are in position, hopefully the rest of the characters will fall simply and easily into place around them.
So why are these three so important? Well, Superman was literally the first modern superhero (yes, yes, there's a lot of debate about this, I read Men of Tomorrow too), Batman is the aspirational evolution of the noir mystery man, and Wonder Woman is, well, a girl.
Urf. That's the second faint praise of Wonder Woman so far. I promise I'll make it up to you, Diana. But seriously, having a female lead hero in the 1940s is a pretty Big Deal. We may not get the same sense of how groundbreaking a character she is in this modern age of refrigerators, but I digress.
Anyways, the next three posts will be about Superman, Batman, and Wonder Woman - who they are and what they're up to come the start of Issue #1.