I was wondering how much is too much to put in the first chapter. I'm only 1500 words into this new project I'm working on and I've already introduced the relationships between the 3 main characters and gone in depth into their past for two of them. Is it too much to put in the first chapter? Should I wait and slowly reveal their pasts as I get further into the book?
Depends on how you've done it. For example, the way you put it in your post, it seems like you just gave the reader a big info dump. With only 1500 words worth of story and already knowing the characters "in depth," we (the readers) will be more likely bored because nothing of actual interest has happened for the story to start. I would suggest that you explain their relationships as the story progresses, rather than getting it done at the start. That way you keep your readers interested and they won't have to go to the beginning of the book to see why "A" character is behaving like he is to character "B" because you didn't explained it at the moment, and assumed that since you had already explained it you didn't need to do it again.
I might just have one of those radical, evil, free-thinking ideas here, but why use chapters? I've seen plenty of books that do quite well with no chapters, and it allows you to freely write your book without a rigid framework getting in the way. If you have a story to tell, just tell it, and let the chapters snap in later, if they fit.
I would personally build it up, allow the reader the take in the information and get the story going from the start. The first chapter is meant to be exciting, so make so it's pretty fast, but plenty of things are happening.
Write story, not back story. Stay in the now. It has no bearing on chapter length and content, but on the approach. It sounds like you're trying too hard to set your characters in stone, at the expense of story development.
It doesn't necessarily have to have a lot of things "happening" to be a good start. You have action vs active openings. Action openings are all well and good but it's the active openings that catch an agent's eye and they're not the same thing. As for the length of a chapter, that's up to you. I look at a novel as a movie that i'm putting onto paper instead of film or pixels. A chapter is a scene, or two scenes if a POV changes to a second character, with proper breakage to allow the reader to change with you, and when it's done, or it's hit the climax, then I move on. There's just so many schools of thought on that subject. I have a lot of short, 7-8 pages typed chapters in my novel, and some, near the end that are longer because they contain tons of action in the scene so it can't be broken up, per se. Only you know the pace of your story and you, the author, have to decide how long/short they are due to pacing, etc
